code: public String resolveLastaEnvPath(String envPath) {
          if (envPath == null) {
              throw new IllegalArgumentException("The argument 'envPath' should not be null.");
          }
          final String lastaEnv = getLastaEnv();
          if (lastaEnv != null && envPath.contains("_env.")) { // e.g. maihama_env.properties to maihama_env_prod.properties
              final String front = LdiSrl.substringLastFront(envPath, "_env.");
              final String rear = LdiSrl.substringLastRear(envPath, "_env.");
              return front + "_env_" + lastaEnv + "." + rear;
          } else {
              return envPath;
          }
      }
docs: ==================