code: def _import_marshaller_modules(self, m):
          
          try:
              for name in m.required_modules:
                  if name not in sys.modules:
                      if _has_importlib:
                          importlib.import_module(name)
                      else:
                          __import__(name)
          except ImportError:
              return False
          except:
              raise
          else:
              return True
docs: Imports the modules required by the marshaller.
  
          Parameters
          ----------
          m : marshaller
              The marshaller to load the modules for.
  
          Returns
          -------
          success : bool
              Whether the modules `m` requires could be imported
              successfully or not.