code: @Override
      public void stateChanged(final CssProperty stateChangedObject) {
  
          if (stateChangedObject instanceof MarginTop) {
              final MarginTop marginTop = (MarginTop) stateChangedObject;
              if (MarginTop.INITIAL.equals(marginTop.getCssValue())
                      || MarginTop.INHERIT.equals(marginTop.getCssValue())) {
                  throw new InvalidValueException(
                          "marginTop cannot have initial/inherit as its cssValue");
              }
          } else if (stateChangedObject instanceof MarginRight) {
              final MarginRight marginRight = (MarginRight) stateChangedObject;
              if (MarginRight.INITIAL.equals(marginRight.getCssValue())
                      || MarginRight.INHERIT.equals(marginRight.getCssValue())) {
                  throw new InvalidValueException(
                          "marginRight cannot have initial/inherit as its cssValue");
              }
          } else if (stateChangedObject instanceof MarginBottom) {
              final MarginBottom marginBottom = (MarginBottom) stateChangedObject;
              if (MarginBottom.INITIAL.equals(marginBottom.getCssValue())
                      || MarginBottom.INHERIT
                              .equals(marginBottom.getCssValue())) {
                  throw new InvalidValueException(
                          "marginBottom cannot have initial/inherit as its cssValue");
              }
          } else if (stateChangedObject instanceof MarginLeft) {
              final MarginLeft marginLeft = (MarginLeft) stateChangedObject;
              if (MarginLeft.INITIAL.equals(marginLeft.getCssValue())
                      || MarginLeft.INHERIT.equals(marginLeft.getCssValue())) {
                  throw new InvalidValueException(
                          "marginLeft cannot have initial/inherit as its cssValue");
              }
          }
  
          assignProducedCssValue(marginTop, marginRight, marginBottom,
                  marginLeft);
  
      }
docs: /*
  (non-Javadoc)
  
  @see
  com.webfirmframework.wffweb.informer.StateChangeInformer#stateChanged(
  java.lang .Object)