@classmethod
def from_node(cls, node, **kwargs):
    """Clone a node with some changes from another one
        """
    return cls(left_ref=kwargs.get('left_ref', node.left_ref), key=kwargs.
        get('key', node.key), value_ref=kwargs.get('value_ref', node.
        value_ref), right_ref=kwargs.get('right_ref', node.right_ref),
        color=kwargs.get('color', node.color))
