code: def __init__(
      self, variable_definitions: Iterable[VariableDefinition]
  ):
      variable_definitions = list(variable_definitions)
      if not variable_definitions:
          raise ValueError("The variable definitions cannot be empty")
      all_variables: list[Variable]
      self.primary_variables, all_variables = typify_variables(
          variable_definitions
      )
      self._derived_start = len(all_variables)
  
      all_variables += interactions(
          variable_definitions, self.primary_variables
      )
      all_variables += missing(all_variables)
  
      self._missing_field_indices = missing_field_indices(all_variables)
      self._interaction_indices = interaction_indices(all_variables)
  
      self._len = len(all_variables)
  
imports: from __future__ import annotations
  import copyreg
  import pkgutil
  import types
  from typing import TYPE_CHECKING, cast
  import numpy
  import dedupe.variables
  from dedupe.variables.base import FieldType
  from dedupe.variables.base import MissingDataType, Variable
  from dedupe.variables.interaction import InteractionType
label_desc: Use image node_id 1 to create a new DataModel object from inherited base classes: object with example: obj = DataModel(variable_definitions)