code: @Override
      public String toBELLongForm() {
          StringBuilder belBuilder = new StringBuilder();
          String fs = function.getDisplayValue();
          belBuilder.append(fs).append("(");
          if (hasItems(functionArgs)) {
              for (BELObject functionArg : functionArgs) {
                  belBuilder.append(functionArg.toBELLongForm());
                  belBuilder.append(",");
              }
              belBuilder.deleteCharAt(belBuilder.length() - 1);
          }
          belBuilder.append(")");
          return belBuilder.toString();
      }
docs: {@inheritDoc}