presto-verifier/src/main/java/io/prestosql/verifier/VerifyCommand.java/VerifyCommand/getQueryDatabase
class VerifyCommand:    protected ConnectionFactory getQueryDatabase(Injector injector)
    {
        VerifierConfig config = injector.getInstance(VerifierConfig.class);
        return () -> DriverManager.getConnection(config.getQueryDatabase());
    }