@property<EOL><INDENT>def phone_number_sid(self):<DEDENT>
return self._properties['<STR_LIT>']<EOL>
:returns: If the call was inbound, this is the SID of the IncomingPhoneNumber resource that received the call. If the call was outbound, it is the SID of the OutgoingCallerId resource from which the call was placed.
:rtype: unicode