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.

def _import_marshaller_modules(self, m):
        """ 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.

        """
        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