Return True if this AdfKey contains the given subkey.

        Parameters
        ----------
        subkey : str or AdfKey
            A key name or an AdfKey object.

        Returns
        -------
        has : bool
            True if this key contains the given key. Otherwise False.

def has_subkey(self, subkey):
        """
        Return True if this AdfKey contains the given subkey.

        Parameters
        ----------
        subkey : str or AdfKey
            A key name or an AdfKey object.

        Returns
        -------
        has : bool
            True if this key contains the given key. Otherwise False.

        """
        if isinstance(subkey, str):
            key = subkey
        elif isinstance(subkey, AdfKey):
            key = subkey.key
        else:
            raise ValueError("The subkey should be an AdfKey or a string!")
        if len(self.subkeys) > 0:
            if key in map(lambda k: k.key, self.subkeys):
                return True
        return False