Add test coverage for getIdentity() with no identity present #819

Job	Run time
testsuite / testsuite-linux (8.4, highest, false)	1m 17s
cs-stan / Coding Standard & Static Analysis	26s
testsuite / testsuite-linux (8.2, lowest, false)	30s
testsuite / testsuite-linux (8.3, highest, false)	40s
testsuite / testsuite-linux (8.2, highest, false)	38s
testsuite / testsuite-linux (8.5, highest, false)	1m 22s
	4m 53s

Provide feedback