code: def build_request_to_validator_map(schema, resolver):
      
      schema_models = schema.get('models', {})
      return dict(
          (
              RequestMatcher(api['path'], operation['method']),
              ValidatorMap.from_operation(operation, schema_models, resolver)
          )
          for api in schema['apis']
          for operation in api['operations']
      )
docs: Build a mapping from :class:`RequestMatcher` to :class:`ValidatorMap`
      for each operation in the API spec. This mapping may be used to retrieve
      the appropriate validators for a request.