def flip_check(intron, flip_dict):
    """
    Checks an intron against a dictionary of introns with scores
    that did not survive boundary switching.

    If present, the score resulting from the boundary switch
    will be returned, otherwise None.

    """
    name = intron.get_name()
    if name in flip_dict:
        return flip_dict[name]
    else:
        return None