old_contents: """PyVizier classes for Pythia policies."""
  
  from vizier._src.pyvizier.pythia.study import StudyDescriptor
  from vizier._src.pyvizier.pythia.study import StudyState
  from vizier._src.pyvizier.pythia.study import StudyStateInfo
  from vizier._src.pyvizier.shared.base_study_config import MetricInformation
  from vizier._src.pyvizier.shared.base_study_config import MetricsConfig
  from vizier._src.pyvizier.shared.base_study_config import MetricType
  from vizier._src.pyvizier.shared.base_study_config import ObjectiveMetricGoal
  from vizier._src.pyvizier.shared.base_study_config import ProblemStatement
  from vizier._src.pyvizier.shared.base_study_config import SearchSpace
  from vizier._src.pyvizier.shared.base_study_config import SearchSpaceSelector
  from vizier._src.pyvizier.shared.common import Metadata
  from vizier._src.pyvizier.shared.common import MetadataValue
  from vizier._src.pyvizier.shared.common import Namespace
  from vizier._src.pyvizier.shared.parameter_config import ExternalType
  from vizier._src.pyvizier.shared.parameter_config import MonotypeParameterSequence
  from vizier._src.pyvizier.shared.parameter_config import ParameterConfig
  from vizier._src.pyvizier.shared.parameter_config import ParameterType
  from vizier._src.pyvizier.shared.parameter_config import ScaleType
  from vizier._src.pyvizier.shared.trial import CompletedTrial
  from vizier._src.pyvizier.shared.trial import Measurement
  from vizier._src.pyvizier.shared.trial import MetadataDelta
  from vizier._src.pyvizier.shared.trial import Metric
  from vizier._src.pyvizier.shared.trial import ParameterDict
  from vizier._src.pyvizier.shared.trial import ParameterValue
  from vizier._src.pyvizier.shared.trial import ParameterValueTypes
  from vizier._src.pyvizier.shared.trial import Trial
  from vizier._src.pyvizier.shared.trial import TrialFilter
  from vizier._src.pyvizier.shared.trial import TrialStatus
  from vizier._src.pyvizier.shared.trial import TrialSuggestion
  
  FlatSpace = SearchSpace
  StudyConfig = ProblemStatement  # To be deprecated.
  
new_contents: """PyVizier classes for Pythia policies."""
  
  from vizier._src.pyvizier.pythia.study import StudyDescriptor
  from vizier._src.pyvizier.pythia.study import StudyState
  from vizier._src.pyvizier.pythia.study import StudyStateInfo
  from vizier._src.pyvizier.shared.base_study_config import MetricInformation
  from vizier._src.pyvizier.shared.base_study_config import MetricsConfig
  from vizier._src.pyvizier.shared.base_study_config import MetricType
  from vizier._src.pyvizier.shared.base_study_config import ObjectiveMetricGoal
  from vizier._src.pyvizier.shared.base_study_config import ProblemStatement
  from vizier._src.pyvizier.shared.base_study_config import SearchSpace
  from vizier._src.pyvizier.shared.base_study_config import SearchSpaceSelector
  from vizier._src.pyvizier.shared.common import Metadata
  from vizier._src.pyvizier.shared.common import MetadataValue
  from vizier._src.pyvizier.shared.common import Namespace
  from vizier._src.pyvizier.shared.parameter_config import ExternalType
  from vizier._src.pyvizier.shared.parameter_config import MonotypeParameterSequence
  from vizier._src.pyvizier.shared.parameter_config import ParameterConfig
  from vizier._src.pyvizier.shared.parameter_config import ParameterType
  from vizier._src.pyvizier.shared.parameter_config import ScaleType
  from vizier._src.pyvizier.shared.trial import CompletedTrial
  from vizier._src.pyvizier.shared.trial import Measurement
  from vizier._src.pyvizier.shared.trial import MetadataDelta
  from vizier._src.pyvizier.shared.trial import Metric
  from vizier._src.pyvizier.shared.trial import ParameterDict
  from vizier._src.pyvizier.shared.trial import ParameterValue
  from vizier._src.pyvizier.shared.trial import ParameterValueTypes
  from vizier._src.pyvizier.shared.trial import Trial
  from vizier._src.pyvizier.shared.trial import TrialFilter
  from vizier._src.pyvizier.shared.trial import TrialStatus
  from vizier._src.pyvizier.shared.trial import TrialSuggestion
  
  FlatSpace = SearchSpace
  StudyConfig = ProblemStatement  # TODO: Deprecate
  
subject: Add a TODO item.