code: private boolean assertValidParams() {
          return username != null && !this.username.isEmpty() &&
                  password != null && !this.password.isEmpty() &&
                  sqlString != null && !this.sqlString.isEmpty() &&
          ( (database != null && !this.database.isEmpty()) || (jdbcConnString != null && !jdbcConnString.isEmpty()) );
      }
docs: This function will check that required parameters
  are set
  @return bool