def METHOD_NAME(self, googleIdToken):
    verifier = GoogleIdTokenVerifier.Builder(NetHttpTransport(), JacksonFactory()).setAudience(Collections.singletonList(self.client_id)).build()
    # the GoogleIdTokenVerifier.verify() method verifies the JWT signature, the aud claim, the iss claim, and the exp claim.
    idToken = verifier.verify(googleIdToken)
    if idToken is not  None:
        payload = idToken.getPayload()
        userId = payload.getSubject()
        print "User ID: %s"  % userId
        #email = payload.getEmail()
        #emailVerified = Boolean.valueOf(payload.getEmailVerified())
        #name = str( payload.get("name"))
        #pictureUrl = str(payload.get("picture"))
        #locale = str( payload.get("locale"))
        #familyName = str( payload.get("family_name"))
        #givenName = str( payload.get("given_name"))
        return userId
    else :
        print "Invalid ID token."
        return None