code: def operations_map(self):
          # type: () -> Dict[Union[str, None], str]
          
          document_ast = self.document_ast
          operations = {}  # type: Dict[Union[str, None], str]
          for definition in document_ast.definitions:
              if isinstance(definition, ast.OperationDefinition):
                  if definition.name:
                      operations[definition.name.value] = definition.operation
                  else:
                      operations[None] = definition.operation
  
          return operations
docs: returns a Mapping of operation names and it's associated types.
          E.g. {'myQuery': 'query', 'myMutation': 'mutation'}