#!/usr/bin/env python3
# Copyright (c) Meta Platforms, Inc. and affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
# pyre-strict
import warnings
from pathlib import Path
from typing import Any
from ax.core import Experiment, ObservationFeatures
from ax.core.arm import Arm
from ax.core.auxiliary import AuxiliaryExperiment
from ax.core.batch_trial import BatchTrial
from ax.core.data import Data
from ax.core.generator_run import GeneratorRun
from ax.core.map_data import MapData, MapKeyInfo
from ax.core.metric import Metric
from ax.core.multi_type_experiment import MultiTypeExperiment
from ax.core.objective import MultiObjective, Objective, ScalarizedObjective
from ax.core.optimization_config import (
MultiObjectiveOptimizationConfig,
OptimizationConfig,
)
from ax.core.outcome_constraint import OutcomeConstraint
from ax.core.parameter import ChoiceParameter, FixedParameter, RangeParameter
from ax.core.parameter_constraint import (
OrderConstraint,
ParameterConstraint,
SumConstraint,
)
from ax.core.parameter_distribution import ParameterDistribution
from ax.core.risk_measures import RiskMeasure
from ax.core.runner import Runner
from ax.core.search_space import RobustSearchSpace, SearchSpace
from ax.core.trial import Trial
from ax.early_stopping.strategies import (
LogicalEarlyStoppingStrategy,
PercentileEarlyStoppingStrategy,
ThresholdEarlyStoppingStrategy,
)
from ax.exceptions.core import AxStorageWarning
from ax.exceptions.storage import JSONEncodeError, STORAGE_DOCS_SUFFIX
from ax.global_stopping.strategies.improvement import ImprovementGlobalStoppingStrategy
from ax.modelbridge.best_model_selector import BestModelSelector
from ax.modelbridge.generation_node import GenerationNode
from ax.modelbridge.generation_strategy import GenerationStep, GenerationStrategy
from ax.modelbridge.model_spec import FactoryFunctionModelSpec, ModelSpec
from ax.modelbridge.registry import _encode_callables_as_references
from ax.modelbridge.transforms.base import Transform
from ax.modelbridge.transition_criterion import TransitionCriterion
from ax.models.torch.botorch_modular.model import BoTorchModel
from ax.models.torch.botorch_modular.surrogate import Surrogate
from ax.models.winsorization_config import WinsorizationConfig
from ax.storage.botorch_modular_registry import CLASS_TO_REGISTRY
from ax.storage.transform_registry import TRANSFORM_REGISTRY
from ax.utils.common.serialization import serialize_init_args
from ax.utils.common.typeutils_torch import torch_type_to_str
from botorch.models.transforms.input import ChainedInputTransform, InputTransform
from botorch.sampling.base import MCSampler
from botorch.utils.types import _DefaultType
from torch import Tensor
[docs]
def experiment_to_dict(experiment: Experiment) -> dict[str, Any]:
"""Convert Ax experiment to a dictionary."""
return {
"__type": experiment.__class__.__name__,
"name": experiment._name,
"description": experiment.description,
"experiment_type": experiment.experiment_type,
"search_space": experiment.search_space,
"optimization_config": experiment.optimization_config,
"tracking_metrics": list(experiment._tracking_metrics.values()),
"runner": experiment.runner,
"status_quo": experiment.status_quo,
"time_created": experiment.time_created,
"trials": experiment.trials,
"is_test": experiment.is_test,
"data_by_trial": experiment.data_by_trial,
"properties": experiment._properties,
"default_data_type": experiment._default_data_type,
}
[docs]
def multi_type_experiment_to_dict(experiment: MultiTypeExperiment) -> dict[str, Any]:
"""Convert AE multitype experiment to a dictionary."""
multi_type_dict = {
"default_trial_type": experiment._default_trial_type,
"_metric_to_canonical_name": experiment._metric_to_canonical_name,
"_metric_to_trial_type": experiment._metric_to_trial_type,
"_trial_type_to_runner": experiment._trial_type_to_runner,
}
multi_type_dict.update(experiment_to_dict(experiment))
return multi_type_dict
[docs]
def batch_to_dict(batch: BatchTrial) -> dict[str, Any]:
"""Convert Ax batch to a dictionary."""
return {
"__type": batch.__class__.__name__,
"index": batch.index,
"trial_type": batch.trial_type,
"ttl_seconds": batch.ttl_seconds,
"status": batch.status,
"status_quo": batch.status_quo,
"status_quo_weight_override": batch._status_quo_weight_override,
"time_created": batch.time_created,
"time_completed": batch.time_completed,
"time_staged": batch.time_staged,
"time_run_started": batch.time_run_started,
"abandoned_reason": batch.abandoned_reason,
"failed_reason": batch.failed_reason,
"run_metadata": batch.run_metadata,
"stop_metadata": batch.stop_metadata,
"generator_run_structs": batch.generator_run_structs,
"runner": batch.runner,
"abandoned_arms_metadata": batch._abandoned_arms_metadata,
"num_arms_created": batch._num_arms_created,
"optimize_for_power": batch.optimize_for_power,
"generation_step_index": batch._generation_step_index,
"lifecycle_stage": batch.lifecycle_stage,
"properties": batch._properties,
}
[docs]
def trial_to_dict(trial: Trial) -> dict[str, Any]:
"""Convert Ax trial to a dictionary."""
return {
"__type": trial.__class__.__name__,
"index": trial.index,
"trial_type": trial.trial_type,
"ttl_seconds": trial.ttl_seconds,
"status": trial.status,
"time_created": trial.time_created,
"time_completed": trial.time_completed,
"time_staged": trial.time_staged,
"time_run_started": trial.time_run_started,
"abandoned_reason": trial.abandoned_reason,
"failed_reason": trial.failed_reason,
"run_metadata": trial.run_metadata,
"stop_metadata": trial.stop_metadata,
"generator_run": trial.generator_run,
"runner": trial.runner,
"num_arms_created": trial._num_arms_created,
"generation_step_index": trial._generation_step_index,
"properties": trial._properties,
}
[docs]
def range_parameter_to_dict(parameter: RangeParameter) -> dict[str, Any]:
"""Convert Ax range parameter to a dictionary."""
return {
"__type": parameter.__class__.__name__,
"name": parameter.name,
"parameter_type": parameter.parameter_type,
"lower": parameter.lower,
"upper": parameter.upper,
"log_scale": parameter.log_scale,
"logit_scale": parameter.logit_scale,
"digits": parameter.digits,
"is_fidelity": parameter.is_fidelity,
"target_value": parameter.target_value,
}
[docs]
def choice_parameter_to_dict(parameter: ChoiceParameter) -> dict[str, Any]:
"""Convert Ax choice parameter to a dictionary."""
return {
"__type": parameter.__class__.__name__,
"is_ordered": parameter.is_ordered,
"is_task": parameter.is_task,
"name": parameter.name,
"parameter_type": parameter.parameter_type,
"values": parameter.values,
"is_fidelity": parameter.is_fidelity,
"target_value": parameter.target_value,
"dependents": parameter.dependents if parameter.is_hierarchical else None,
}
[docs]
def fixed_parameter_to_dict(parameter: FixedParameter) -> dict[str, Any]:
"""Convert Ax fixed parameter to a dictionary."""
return {
"__type": parameter.__class__.__name__,
"name": parameter.name,
"parameter_type": parameter.parameter_type,
"value": parameter.value,
"is_fidelity": parameter.is_fidelity,
"target_value": parameter.target_value,
"dependents": parameter.dependents if parameter.is_hierarchical else None,
}
[docs]
def order_parameter_constraint_to_dict(
parameter_constraint: OrderConstraint,
) -> dict[str, Any]:
"""Convert Ax order parameter constraint to a dictionary."""
return {
"__type": parameter_constraint.__class__.__name__,
"lower_name": parameter_constraint.lower_parameter.name,
"upper_name": parameter_constraint.upper_parameter.name,
}
[docs]
def sum_parameter_constraint_to_dict(
parameter_constraint: SumConstraint,
) -> dict[str, Any]:
"""Convert Ax sum parameter constraint to a dictionary."""
return {
"__type": parameter_constraint.__class__.__name__,
"parameter_names": parameter_constraint._parameter_names,
"is_upper_bound": parameter_constraint._is_upper_bound,
# SumParameterConstraint constructor takes in absolute value of
# the bound and transforms it based on the is_upper_bound value
"bound": abs(parameter_constraint._bound),
}
[docs]
def parameter_constraint_to_dict(
parameter_constraint: ParameterConstraint,
) -> dict[str, Any]:
"""Convert Ax sum parameter constraint to a dictionary."""
return {
"__type": parameter_constraint.__class__.__name__,
"constraint_dict": parameter_constraint.constraint_dict,
"bound": parameter_constraint.bound,
}
[docs]
def arm_to_dict(arm: Arm) -> dict[str, Any]:
"""Convert Ax arm to a dictionary."""
return {
"__type": arm.__class__.__name__,
"parameters": arm.parameters,
"name": arm._name,
}
[docs]
def search_space_to_dict(search_space: SearchSpace) -> dict[str, Any]:
"""Convert Ax search space to a dictionary."""
return {
"__type": search_space.__class__.__name__,
"parameters": list(search_space.parameters.values()),
"parameter_constraints": search_space.parameter_constraints,
}
[docs]
def robust_search_space_to_dict(rss: RobustSearchSpace) -> dict[str, Any]:
"""Convert robust search space to a dictionary."""
return {
"__type": rss.__class__.__name__,
"parameters": list(rss._parameters.values()),
"parameter_distributions": rss.parameter_distributions,
"num_samples": rss.num_samples,
"environmental_variables": list(rss._environmental_variables.values()),
"parameter_constraints": rss.parameter_constraints,
}
[docs]
def parameter_distribution_to_dict(dist: ParameterDistribution) -> dict[str, Any]:
"""Convert a parameter distribution to a dictionary."""
return {
"__type": dist.__class__.__name__,
"parameters": dist.parameters,
"distribution_class": dist.distribution_class,
"distribution_parameters": dist.distribution_parameters,
"multiplicative": dist.multiplicative,
}
[docs]
def metric_to_dict(metric: Metric) -> dict[str, Any]:
"""Convert Ax metric to a dictionary."""
properties = metric.serialize_init_args(obj=metric)
properties["__type"] = metric.__class__.__name__
return properties
[docs]
def objective_to_dict(objective: Objective) -> dict[str, Any]:
"""Convert Ax objective to a dictionary."""
return {
"__type": objective.__class__.__name__,
"metric": objective.metric,
"minimize": objective.minimize,
}
[docs]
def multi_objective_to_dict(objective: MultiObjective) -> dict[str, Any]:
"""Convert Ax objective to a dictionary."""
return {
"__type": objective.__class__.__name__,
"objectives": objective.objectives,
"weights": objective.weights,
}
[docs]
def scalarized_objective_to_dict(objective: ScalarizedObjective) -> dict[str, Any]:
"""Convert Ax objective to a dictionary."""
return {
"__type": objective.__class__.__name__,
"metrics": objective.metrics,
"weights": objective.weights,
"minimize": objective.minimize,
}
[docs]
def outcome_constraint_to_dict(outcome_constraint: OutcomeConstraint) -> dict[str, Any]:
"""Convert Ax outcome constraint to a dictionary."""
return {
"__type": outcome_constraint.__class__.__name__,
"metric": outcome_constraint.metric,
"op": outcome_constraint.op,
"bound": outcome_constraint.bound,
"relative": outcome_constraint.relative,
}
[docs]
def optimization_config_to_dict(
optimization_config: OptimizationConfig,
) -> dict[str, Any]:
"""Convert Ax optimization config to a dictionary."""
return {
"__type": optimization_config.__class__.__name__,
"objective": optimization_config.objective,
"outcome_constraints": optimization_config.outcome_constraints,
"risk_measure": optimization_config.risk_measure,
}
[docs]
def multi_objective_optimization_config_to_dict(
multi_objective_optimization_config: MultiObjectiveOptimizationConfig,
) -> dict[str, Any]:
"""Convert Ax optimization config to a dictionary."""
return {
"__type": multi_objective_optimization_config.__class__.__name__,
"objective": multi_objective_optimization_config.objective,
"outcome_constraints": multi_objective_optimization_config.outcome_constraints,
"objective_thresholds": multi_objective_optimization_config.objective_thresholds, # noqa E501
"risk_measure": multi_objective_optimization_config.risk_measure,
}
[docs]
def generator_run_to_dict(generator_run: GeneratorRun) -> dict[str, Any]:
"""Convert Ax generator run to a dictionary."""
gr = generator_run
cand_metadata = gr.candidate_metadata_by_arm_signature
return {
"__type": gr.__class__.__name__,
"arms": gr.arms,
"weights": gr.weights,
"optimization_config": gr.optimization_config,
"search_space": gr.search_space,
"time_created": gr.time_created,
"model_predictions": gr.model_predictions,
"best_arm_predictions": gr.best_arm_predictions,
"generator_run_type": gr.generator_run_type,
"index": gr.index,
"fit_time": gr.fit_time,
"gen_time": gr.gen_time,
"model_key": gr._model_key,
"model_kwargs": gr._model_kwargs,
"bridge_kwargs": gr._bridge_kwargs,
"gen_metadata": gr._gen_metadata,
"model_state_after_gen": gr._model_state_after_gen,
"generation_step_index": gr._generation_step_index,
"candidate_metadata_by_arm_signature": cand_metadata,
"generation_node_name": gr._generation_node_name,
}
[docs]
def runner_to_dict(runner: Runner) -> dict[str, Any]:
"""Convert Ax runner to a dictionary."""
properties = runner.serialize_init_args(obj=runner)
properties["__type"] = runner.__class__.__name__
return properties
[docs]
def data_to_dict(data: Data) -> dict[str, Any]:
"""Convert Ax data to a dictionary."""
properties = data.serialize_init_args(obj=data)
properties["__type"] = data.__class__.__name__
return properties
[docs]
def map_data_to_dict(map_data: MapData) -> dict[str, Any]:
"""Convert Ax map data to a dictionary."""
properties = map_data.serialize_init_args(obj=map_data)
properties["__type"] = map_data.__class__.__name__
return properties
# pyre-fixme[24]: Generic type `MapKeyInfo` expects 1 type parameter.
[docs]
def map_key_info_to_dict(mki: MapKeyInfo) -> dict[str, Any]:
"""Convert Ax map data metadata to a dictionary."""
properties = serialize_init_args(obj=mki)
properties["__type"] = mki.__class__.__name__
return properties
[docs]
def generation_step_to_dict(generation_step: GenerationStep) -> dict[str, Any]:
"""Converts Ax generation step to a dictionary."""
return {
"__type": generation_step.__class__.__name__,
"model": generation_step.model,
"num_trials": generation_step.num_trials,
"min_trials_observed": generation_step.min_trials_observed,
"completion_criteria": generation_step.completion_criteria,
"max_parallelism": generation_step.max_parallelism,
"use_update": generation_step.use_update,
"enforce_num_trials": generation_step.enforce_num_trials,
"model_kwargs": _encode_callables_as_references(
generation_step.model_kwargs or {}
),
"model_gen_kwargs": _encode_callables_as_references(
generation_step.model_gen_kwargs or {}
),
"index": generation_step.index,
"should_deduplicate": generation_step.should_deduplicate,
"transition_criteria": generation_step.transition_criteria,
}
[docs]
def generation_node_to_dict(generation_node: GenerationNode) -> dict[str, Any]:
"""Convert Ax generation node to a dictionary."""
return {
"__type": generation_node.__class__.__name__,
"node_name": generation_node.node_name,
"model_specs": generation_node.model_specs,
"best_model_selector": generation_node.best_model_selector,
"should_deduplicate": generation_node.should_deduplicate,
"transition_criteria": generation_node.transition_criteria,
"model_spec_to_gen_from": generation_node._model_spec_to_gen_from,
"previous_node_name": generation_node._previous_node_name,
"trial_type": generation_node._trial_type,
# need to manually encode input constructors because the key is an enum.
# Our encoding and decoding logic in object_to_json and object_from_json
# doesn't recursively encode/decode the keys of dictionaries.
"input_constructors": {
key.name: value for key, value in generation_node.input_constructors.items()
},
}
[docs]
def generation_strategy_to_dict(
generation_strategy: GenerationStrategy,
) -> dict[str, Any]:
"""Converts Ax generation strategy to a dictionary."""
if generation_strategy.uses_non_registered_models:
raise ValueError(
"Generation strategies that use custom models provided through "
"callables cannot be serialized and stored."
)
node_based_gs = generation_strategy.is_node_based
return {
"__type": generation_strategy.__class__.__name__,
"db_id": generation_strategy._db_id,
"name": generation_strategy.name,
"steps": generation_strategy._steps if not node_based_gs else [],
"curr_index": (
generation_strategy.current_step_index if not node_based_gs else -1
),
"generator_runs": generation_strategy._generator_runs,
"had_initialized_model": generation_strategy.model is not None,
"experiment": generation_strategy._experiment,
"nodes": generation_strategy._nodes,
"curr_node_name": generation_strategy.current_node_name,
}
[docs]
def transition_criterion_to_dict(criterion: TransitionCriterion) -> dict[str, Any]:
"""Convert Ax TransitionCriterion to a dictionary."""
properties = criterion.serialize_init_args(obj=criterion)
properties["__type"] = criterion.__class__.__name__
return properties
[docs]
def model_spec_to_dict(model_spec: ModelSpec) -> dict[str, Any]:
"""Convert Ax model spec to a dictionary."""
if isinstance(model_spec, FactoryFunctionModelSpec):
raise NotImplementedError(
f"JSON serialization not yet implemented for model spec: {model_spec}"
" because it leverages a factory function instead of `Models` registry."
)
return {
"__type": model_spec.__class__.__name__,
"model_enum": model_spec.model_enum,
"model_kwargs": model_spec.model_kwargs,
"model_gen_kwargs": model_spec.model_gen_kwargs,
}
[docs]
def best_model_selector_to_dict(
best_model_selector: BestModelSelector,
) -> dict[str, Any]:
"""Convert ``BestModelSelector`` to a dictionary."""
return {
"__type": best_model_selector.__class__.__name__,
**serialize_init_args(obj=best_model_selector),
}
[docs]
def observation_features_to_dict(obs_features: ObservationFeatures) -> dict[str, Any]:
"""Converts Ax observation features to a dictionary"""
return {
"__type": obs_features.__class__.__name__,
"parameters": obs_features.parameters,
"trial_index": obs_features.trial_index,
"start_time": obs_features.start_time,
"end_time": obs_features.end_time,
"random_split": obs_features.random_split,
"metadata": obs_features.metadata,
}
[docs]
def botorch_model_to_dict(model: BoTorchModel) -> dict[str, Any]:
"""Convert Ax model to a dictionary."""
return {
"__type": model.__class__.__name__,
"acquisition_class": model.acquisition_class,
"acquisition_options": model.acquisition_options or {},
"surrogate": (model._surrogate if model.surrogate_spec is None else None),
"surrogate_spec": model.surrogate_spec,
"botorch_acqf_class": model._botorch_acqf_class,
"refit_on_cv": model.refit_on_cv,
"warm_start_refit": model.warm_start_refit,
}
[docs]
def surrogate_to_dict(surrogate: Surrogate) -> dict[str, Any]:
"""Convert Ax surrogate to a dictionary."""
dict_representation = {"__type": surrogate.__class__.__name__}
dict_representation.update(surrogate._serialize_attributes_as_kwargs())
return dict_representation
[docs]
def tensor_to_dict(obj: Tensor) -> dict[str, Any]:
if obj.numel() > 1e4:
warnings.warn(
f"Attempting to serialize a tensor with {obj.numel()} elements. "
"This may result in storage issues.",
AxStorageWarning,
stacklevel=3,
)
return {
"__type": "Tensor",
"value": obj.tolist(),
"dtype": {"__type": "torch_dtype", "value": torch_type_to_str(obj.dtype)},
"device": {"__type": "torch_device", "value": torch_type_to_str(obj.device)},
}
# pyre-fixme[2]: Parameter annotation cannot contain `Any`.
[docs]
def botorch_modular_to_dict(class_type: type[Any]) -> dict[str, Any]:
"""Convert any class to a dictionary."""
for _class in CLASS_TO_REGISTRY:
if issubclass(class_type, _class):
registry = CLASS_TO_REGISTRY[_class]
if class_type not in registry:
raise ValueError(
f"Class `{class_type.__name__}` not in Type[{_class.__name__}] "
"registry, please add it. BoTorch object registries are "
"located in `ax/storage/botorch_modular_registry.py`. "
f"{STORAGE_DOCS_SUFFIX}"
)
return {
"__type": f"Type[{_class.__name__}]",
"index": registry[class_type],
"class": f"{_class}",
}
raise ValueError(
f"{class_type} does not have a corresponding parent class in "
f"CLASS_TO_REGISTRY. {STORAGE_DOCS_SUFFIX}"
)
# pyre-fixme[2]: Parameter annotation cannot contain `Any`.
[docs]
def botorch_component_to_dict(input_obj: Any) -> dict[str, Any]:
class_type = input_obj.__class__
if isinstance(input_obj, InputTransform):
# Input transforms cannot be initialized with their state dicts.
# We will instead extract the init args.
state_dict = botorch_input_transform_to_init_args(input_transform=input_obj)
else:
state_dict = dict(input_obj.state_dict())
if isinstance(input_obj, MCSampler):
# The sampler args are not part of the state dict. Manually add them.
# Sample shape cannot be added to torch state dict since it is not a tensor.
state_dict["sample_shape"] = input_obj.sample_shape
state_dict["seed"] = input_obj.seed
return {
"__type": f"{class_type.__name__}",
"index": class_type,
"class": f"{class_type}",
"state_dict": state_dict,
}
[docs]
def percentile_early_stopping_strategy_to_dict(
strategy: PercentileEarlyStoppingStrategy,
) -> dict[str, Any]:
"""Convert Ax percentile early stopping strategy to a dictionary."""
return {
"__type": strategy.__class__.__name__,
"metric_names": strategy.metric_names,
"percentile_threshold": strategy.percentile_threshold,
"min_progression": strategy.min_progression,
"min_curves": strategy.min_curves,
"trial_indices_to_ignore": strategy.trial_indices_to_ignore,
"seconds_between_polls": strategy.seconds_between_polls,
"normalize_progressions": strategy.normalize_progressions,
}
[docs]
def threshold_early_stopping_strategy_to_dict(
strategy: ThresholdEarlyStoppingStrategy,
) -> dict[str, Any]:
"""Convert Ax metric-threshold early stopping strategy to a dictionary."""
return {
"__type": strategy.__class__.__name__,
"metric_names": strategy.metric_names,
"metric_threshold": strategy.metric_threshold,
"min_progression": strategy.min_progression,
"trial_indices_to_ignore": strategy.trial_indices_to_ignore,
"normalize_progressions": strategy.normalize_progressions,
}
[docs]
def logical_early_stopping_strategy_to_dict(
strategy: LogicalEarlyStoppingStrategy,
) -> dict[str, Any]:
return {
"__type": strategy.__class__.__name__,
"left": strategy.left,
"right": strategy.right,
}
[docs]
def improvement_global_stopping_strategy_to_dict(
gss: ImprovementGlobalStoppingStrategy,
) -> dict[str, Any]:
"""Convert ImprovementGlobalStoppingStrategy to a dictionary."""
return {
"__type": gss.__class__.__name__,
"min_trials": gss.min_trials,
"window_size": gss.window_size,
"improvement_bar": gss.improvement_bar,
"inactive_when_pending_trials": gss.inactive_when_pending_trials,
}
[docs]
def winsorization_config_to_dict(config: WinsorizationConfig) -> dict[str, Any]:
"""Convert Ax winsorization config to a dictionary."""
return {
"__type": config.__class__.__name__,
"lower_quantile_margin": config.lower_quantile_margin,
"upper_quantile_margin": config.upper_quantile_margin,
"lower_boundary": config.lower_boundary,
"upper_boundary": config.upper_boundary,
}
[docs]
def risk_measure_to_dict(
risk_measure: RiskMeasure,
) -> dict[str, Any]:
"""Convert a RiskMeasure to a dictionary."""
return {
"__type": risk_measure.__class__.__name__,
"risk_measure": risk_measure.risk_measure,
"options": risk_measure.options,
}
[docs]
def auxiliary_experiment_to_dict(
auxiliary_experiment: AuxiliaryExperiment,
) -> dict[str, Any]:
return {
"__type": auxiliary_experiment.__class__.__name__,
"experiment": auxiliary_experiment.experiment,
"data": auxiliary_experiment.data,
}
[docs]
def pathlib_to_dict(path: Path) -> dict[str, Any]:
return {"__type": path.__class__.__name__, "pathsegments": [str(path)]}
[docs]
def default_to_dict(default: _DefaultType) -> dict[str, Any]:
return {"__type": default.__class__.__name__}
