@properties.ClassProperty<EOL><INDENT>@classmethod<EOL>def backends(cls):<DEDENT>
allowed = (<EOL>keyring<EOL>for keyring in filter(backend._limit, backend.get_all_keyring())<EOL>if not isinstance(keyring, ChainerBackend)<EOL>and keyring.priority > <NUM_LIT:0><EOL>)<EOL>return sorted(allowed, key=backend.by_priority, reverse=True)<EOL>
Discover all keyrings for chaining.