code: def lookup_online(byte_sig: str, timeout: int, proxies=None) -> List[str]:
          
          if not ethereum_input_decoder:
              return []
          return list(
              ethereum_input_decoder.decoder.FourByteDirectory.lookup_signatures(
                  byte_sig, timeout=timeout, proxies=proxies
              )
          )
docs: Lookup function signatures from 4byte.directory.
  
          :param byte_sig: function signature hash as hexstr
          :param timeout: optional timeout for online lookup
          :param proxies: optional proxy servers for online lookup
          :return: a list of matching function signatures for this hash