Append the given bindings to this keymap.

        Arguments:
            *bindings (Binding): Bindings to be added.
        Returns:
            Keymap: self

def extend(self, *bindings):
        """ Append the given bindings to this keymap.

        Arguments:
            *bindings (Binding): Bindings to be added.
        Returns:
            Keymap: self
        """
        self._bindings.extend(self._preprocess(bindings))
        return self