def METHOD_NAME(self, key):  # pylint: disable=arguments-differ
    """
    Remove an element.  Do not raise an exception if absent.
    The MutableSet mixin uses this to implement the .remove() method, which
    *does* raise an error when asked to remove a non-existent item.
    """
    if key in self:
        i = self.map[key]
        del self.items[i]
        del self.map[key]
        for k, v in self.map.items():
            if v >= i:
                self.map[k] = v - 1