code: public DataForm getDataFormToSend() {
          if (isSubmitType()) {
              // Create a new DataForm that contains only the answered fields
              DataForm dataFormToSend = new DataForm(getType());
              for (FormField field : getFields()) {
                  if (!field.getValues().isEmpty()) {
                      dataFormToSend.addField(field);
                  }
              }
              return dataFormToSend;
          }
          return dataForm;
      }
docs: Returns a DataForm that serves to send this Form to the server. If the form is of type
  submit, it may contain fields with no value. These fields will be removed since they only
  exist to assist the user while editing/completing the form in a UI.
  
  @return the wrapped DataForm.