code: public final void setId(final ID id) {
      Assert.notNull(id, "The identifier for Rule ({0}) cannot be null!", getClass().getName());
      this.id = id;
    }
docs: Sets the identifier for this Rule.
  
  @param id a value of type T assigned as this object's unique identifier.
  @see org.cp.elements.lang.Identifiable#setId(Comparable)
  @throws NullPointerException if the identifier for this Rule is null.