code: public boolean remove(VMTransitionBuilder b) {
          Map<VMState, VMTransitionBuilder> m = vmAMB2.get(b.getDestinationState());
          for (VMState src : b.getSourceStates()) {
              m.remove(src);
          }
          return true;
      }
docs: Remove a builder for an action on a VM.
  
  @param b the builder to remove
  @return {@code true} if it has been removed