code: public ResultMatcher isObject() {
          return new AbstractResultMatcher(path, configuration) {
              public void doMatch(Object actual) {
                  isPresent(actual);
                  Node node = getNode(actual);
                  if (node.getNodeType() != OBJECT) {
                      failOnType(node, "an object");
                  }
              }
          };
      }
docs: Fails if the selected JSON is not an Object or is not present.