code: public boolean isChecked() {
          String valueEnabledString = getEnabledValueString();
  
          String currentValue = this.getFirstValue();
          return valueEnabledString.equals(currentValue);
      }
docs: Indicates if the element is considered checked,
  that is, the value is the same as the one configured with {@link #setEnabledValueString(java.lang.String)}.
  @return True if checked, false otherwise