def METHOD_NAME(self, node):
    """Send node to the top of the list (mark it as the MRU)."""
    if node is None:
        return None
    # First item, just set lru & mru
    if not self._data:
        self._lru = node
        self._mru = node
        return node
    # MRU, just return it
    if node is self._mru:
        return node
    # LRU, update pointer and end-of-list
    if node is self._lru:
        self._lru = node.next
        self._lru.previous = None
    if node.previous is not None:
        node.previous.next = node.next
    if node.next is not None:
        node.next.previous = node.previous
    node.previous = self._mru
    node.previous.next = node
    node.next = None
    self._mru = node
    return node