presto-verifier/src/main/java/io/prestosql/verifier/VerifierConfig.java/VerifierConfig/setTestUsernameOverride
class VerifierConfig:    @ConfigDescription("Username for test cluster")
    @Config("test.username-override")
    @LegacyConfig("test.username")
    public VerifierConfig setTestUsernameOverride(String testUsernameOverride)
    {
        this.testUsernameOverride = testUsernameOverride;
        return this;
    }