Split 2 layers previously bound.
    This call un-links calls bind_top_down and bind_bottom_up. It is the opposite of  # noqa: E501
    bind_layers.

    Please have a look at their docs:
     - help(split_bottom_up)
     - help(split_top_down)

def split_layers(lower, upper, __fval=None, **fval):
    """Split 2 layers previously bound.
    This call un-links calls bind_top_down and bind_bottom_up. It is the opposite of  # noqa: E501
    bind_layers.

    Please have a look at their docs:
     - help(split_bottom_up)
     - help(split_top_down)
    """
    if __fval is not None:
        fval.update(__fval)
    split_bottom_up(lower, upper, **fval)
    split_top_down(lower, upper, **fval)