code: def deep_mapping(
      key_validator, value_validator, mapping_validator=None
  ):
      """
      A validator that performs deep validation of a dictionary.
  
      :param key_validator: Validator to apply to dictionary keys
      :param value_validator: Validator to apply to dictionary values
      :param mapping_validator: Validator to apply to top-level mapping
          attribute (optional)
  
      .. versionadded:: 19.1.0
  
      :raises TypeError: if any sub-validators fail
      """
      return _DeepMapping(
          key_validator, value_validator, mapping_validator
      )
  
imports: from __future__ import absolute_import, division, print_function
  import re
  from ._make import _AndValidator, and_, attrib, attrs
  from .exceptions import NotCallableError
label_desc: Use image node_id 8 for calling a global function with example usage: deep_mapping(key_validator, value_validator, mapping_validator) and returns: _DeepMapping