def METHOD_NAME(self, rset=None):
    if not hasattr(self, 'snaps'):
        return
    if len(self.snaps) == 0 :
        return
    for s in list(self.snaps.keys()):
        self.snapdestroykey(s)
    if rset is None:
        return
    for i, r in enumerate(rset.resources):
        if hasattr(rset.resources[i], 'alt_src'):
            delattr(rset.resources[i], 'alt_src')