def METHOD_NAME(self) -> None:
    """Checks for possible clashes and logs warnings."""
    if self.key and self.children:
        hidden: List[str] = []
        for child in self.children.values():
            hidden.extend(key for key, _ in child)
        _logger.warning("%s hides longer keys: %s", self.key, quotedjoin(hidden))
    for child in self.children.values():
        child.METHOD_NAME()