adding few more testcases covering possible scenarios of Q.join() operator.
adding few more testcases covering possible scenarios of Q.join() operator.

NerdWalletOSS/Q,NerdWalletOSS/Q,NerdWalletOSS/Q,NerdWalletOSS/Q,NerdWalletOSS/Q,NerdWalletOSS/Q,NerdWalletOSS/Q,NerdWalletOSS/Q