def __call__(self, sid):
return SigningKeyContext(self._version, account_sid=self._solution['<STR_LIT>'], sid=sid, )<EOL>
Constructs a SigningKeyContext

:param sid: The sid

:returns: twilio.rest.api.v2010.account.signing_key.SigningKeyContext
:rtype: twilio.rest.api.v2010.account.signing_key.SigningKeyContext