def METHOD_NAME(self, variable: typing.Union[str, list[str]]) -> 'DerivedVariableRegistry':
    """Search for a derived variable by name or list of names
    Parameters
    ----------
    variable : typing.Union[str, typing.List[str]]
        The name of the variable to search for.
    Returns
    -------
    DerivedVariableRegistry
        A DerivedVariableRegistry with the found variables.
    """
    if isinstance(variable, str):
        variable = [variable]
    results = tlz.dicttoolz.keyfilter(lambda x: x in variable, self._registry)
    reg = DerivedVariableRegistry()
    reg._registry = results
    return reg