"in which supreme court decision involving an invalidated employment test for firemen did the court state: "once the process has been established and employers have made clear their selection criteria

"in which supreme court decision involving an invalidated employment test for firemen did the court state: "once the process has been established and employers have made clear their selection criteria, they may not then invalidate the test results, thus upsetting an employee's legitimate expectation not to be judged on the basis of race?""