code: public static String getFirstLabel(final LabelOrBuilder label) throws NotAvailableException {
          for (Label.MapFieldEntry entry : label.getEntryList()) {
              for (String value : entry.getValueList()) {
                  return value;
              }
          }
          throw new NotAvailableException("Label");
      }
docs: Get the first label found in the label type. This is independent of the language of the label.
  
  @param label the label type which is searched for the first label
  
  @return the first label found
  
  @throws NotAvailableException if now label is contained in the label type.