def get_schemas(dic):
    """Return a list of all subtypes of the Schema type to feed to __all__"""
    from pyson.schema.schema_class import Schema
    ret_lst = []
    for k, v in dic.items():
        if isinstance(v, type) and issubclass(v, Schema) and not k.startswith(
            '_'):
            ret_lst.append(k)
    return ret_lst
