lookup_consumer()
lookup_nonce()
lookup_token()
new_access_token()
new_request_token()
lookup_consumer($consumer_key)
lookup_nonce($consumer, $token, $nonce, $timestamp)
lookup_token($consumer, $token_type, $token)
new_access_token($token, $consumer, $verifier)
new_request_token($consumer, $callback)