@classmethod
def remove_implicit_resolver(cls, tag):
    """
        Remove an implicit resolver from a Loader class identified by its tag.
        """
    if not 'yaml_implicit_resolvers' in cls.__dict__:
        cls.yaml_implicit_resolvers = cls.yaml_implicit_resolvers.copy()
    for key in cls.yaml_implicit_resolvers:
        resolvers_set = cls.yaml_implicit_resolvers[key]
        for idx in range(len(resolvers_set)):
            if resolvers_set[idx][0] == tag:
                del resolvers_set[idx]
        if len(resolvers_set) == 0:
            del cls.yaml_implicit_resolvers[key]
