docs: @Nonnegative
    public static java.time.Month getMonth (@Nonnull final Month eMonth)
    {
      switch (eMonth)
      {
        case JANUARY:
          return java.time.Month.JANUARY;
        case FEBRUARY:
          return java.time.Month.FEBRUARY;
        case MARCH:
          return java.time.Month.MARCH;
        case APRIL:
          return java.time.Month.APRIL;
        case MAY:
          return java.time.Month.MAY;
        case JUNE:
          return java.time.Month.JUNE;
        case JULY:
          return java.time.Month.JULY;
        case AUGUST:
          return java.time.Month.AUGUST;
        case SEPTEMBER:
          return java.time.Month.SEPTEMBER;
        case OCTOBER:
          return java.time.Month.OCTOBER;
        case NOVEMBER:
          return java.time.Month.NOVEMBER;
        case DECEMBER:
          return java.time.Month.DECEMBER;
        default:
          throw new IllegalArgumentException ("Unknown month " + eMonth);
      }
    }