docs: public boolean equal(final Object o1,
                           Object o2) {
          if ( o1 == o2 ) {
              return true;
              
          }
          // o1 is a FactHandle, so just check their id's are the same
          if ( o1 instanceof FactHandle ) {
              return ((InternalFactHandle)o1).getId() == ((InternalFactHandle)o2).getId() ;
          }
  
          // o1 is an object, so unwrap o2 for comparison
          final InternalFactHandle handle = ((InternalFactHandle) o2);
          o2 = handle.getObject();
          return o1 == o2 || o2.equals( o1 );
      }