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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _ReadConstantDataTypeDefinition( self, definitions_registry, definition_values, definition_name, is_member=False):
 """Reads a constant data type definition. Args: definitions_registry (DataTypeDefinitionsRegistry):
 data type definitions registry. definition_values (dict[str, object]):
 definition values. definition_name (str):
 name of the definition. is_member (Optional[bool]):
 True if the data type definition is a member data type definition. Returns: ConstantDataTypeDefinition: constant data type definition. Raises: DefinitionReaderError: if the definitions values are missing or if the format is incorrect. """

    if is_member:
      error_message = 'data type not supported as member'
      raise errors.DefinitionReaderError(definition_name, error_message)

    value = definition_values.get('value', None)
    if value is None:
      error_message = 'missing value'
      raise errors.DefinitionReaderError(definition_name, error_message)

    definition_object = self._ReadSemanticDataTypeDefinition(
        definitions_registry, definition_values, data_types.ConstantDefinition,
        definition_name, self._SUPPORTED_DEFINITION_VALUES_CONSTANT)
    definition_object.value = value

    return definition_object