public Set<String> getOperatorClasses(String parent, String searchTerm)
      throws ClassNotFoundException {
    if (CollectionUtils.isEmpty(operatorClassNames)) {
      loadOperatorClass();
    }
    if (parent == null) {
      parent = Operator.class.getName();
    } else {
      if (!typeGraph.isAncestor(Operator.class.getName(), parent)) {
        throw new IllegalArgumentException("Argument must be a subclass of Operator class");
      }
    }

    Set<String> filteredClass =
        Sets.filter(
            operatorClassNames,
            new Predicate<String>() {
              @Override
              public boolean apply(String className) {
                OperatorClassInfo oci = classInfo.get(className);
                return oci == null || !oci.tags.containsKey("@omitFromUI");
              }
            });

    if (searchTerm == null && parent.equals(Operator.class.getName())) {
      return filteredClass;
    }

    if (searchTerm != null) {
      searchTerm = searchTerm.toLowerCase();
    }

    Set<String> result = new HashSet<String>();
    for (String clazz : filteredClass) {
      if (parent.equals(Operator.class.getName()) || typeGraph.isAncestor(parent, clazz)) {
        if (searchTerm == null) {
          result.add(clazz);
        } else {
          if (clazz.toLowerCase().contains(searchTerm)) {
            result.add(clazz);
          } else {
            OperatorClassInfo oci = classInfo.get(clazz);
            if (oci != null) {
              if (oci.comment != null && oci.comment.toLowerCase().contains(searchTerm)) {
                result.add(clazz);
              } else {
                for (Map.Entry<String, String> entry : oci.tags.entrySet()) {
                  if (entry.getValue().toLowerCase().contains(searchTerm)) {
                    result.add(clazz);
                    break;
                  }
                }
              }
            }
          }
        }
      }
    }
    return result;
  }
  private JSONObject setFieldAttributes(String clazz, CompactFieldNode field) throws JSONException {
    JSONObject port = new JSONObject();
    port.put("name", field.getName());

    TypeGraphVertex tgv = typeGraph.getTypeGraphVertex(clazz);
    putFieldDescription(field, port, tgv);

    List<CompactAnnotationNode> annotations = field.getVisibleAnnotations();
    CompactAnnotationNode firstAnnotation;
    if (annotations != null
        && !annotations.isEmpty()
        && (firstAnnotation = field.getVisibleAnnotations().get(0)) != null) {
      for (Map.Entry<String, Object> entry : firstAnnotation.getAnnotations().entrySet()) {
        port.put(entry.getKey(), entry.getValue());
      }
    }

    return port;
  }
  private void addTagsToProperties(MethodInfo mi, JSONObject propJ) throws JSONException {
    // create description object. description tag enables the visual tools to display description of
    // keys/values
    // of a map property, items of a list, properties within a complex type.
    JSONObject descriptionObj = new JSONObject();
    if (mi.comment != null) {
      descriptionObj.put("$", mi.comment);
    }
    for (Map.Entry<String, String> descEntry : mi.descriptions.entrySet()) {
      descriptionObj.put(descEntry.getKey(), descEntry.getValue());
    }
    if (descriptionObj.length() > 0) {
      propJ.put("descriptions", descriptionObj);
    }

    // create useSchema object. useSchema tag is added to enable visual tools to be able to render a
    // text field
    // as a dropdown with choices populated from the schema attached to the port.
    JSONObject useSchemaObj = new JSONObject();
    for (Map.Entry<String, String> useSchemaEntry : mi.useSchemas.entrySet()) {
      useSchemaObj.put(useSchemaEntry.getKey(), useSchemaEntry.getValue());
    }
    if (useSchemaObj.length() > 0) {
      propJ.put("useSchema", useSchemaObj);
    }
  }