docs: public List<Invocation> find(List<?> mocks) {
          List<Invocation> unused = new LinkedList<Invocation>();
          for (Object mock : mocks) {
              List<Stubbing> fromSingleMock = MockUtil.getInvocationContainer(mock).getStubbingsDescending();
              for(Stubbing s : fromSingleMock) {
                  if (!s.wasUsed()) {
                       unused.add(s.getInvocation());
                  }
              }
          }
          return unused;
      }