public void setPropertyValue(final Object id, final Object value) {
Object oldValue = getPropertyValue(id);
if (oldValue == value || (oldValue != null && oldValue.equals(value))) {
return;
}
Command c = new ChangeAttributeCommand(
PDPlugin
.getResourceString("AttributePropertySource.CommandLabel.ChangeAttribute"), _element, (String) id, (String) value); //$NON-NLS-1$
c.execute();
}