How to use javafx.collections

@Override
public void setValidators(ValidatorBase... validators) {
  this.validators.addAll(validators);
}

  @Override
  public void onChanged(javafx.collections.ListChangeListener.Change<? extends Node> c) {
    while (c.next()) {
      if (!c.wasPermutated() && !c.wasUpdated()) {
        for (Node addedNode : c.getAddedSubList()) {
          if (addedNode instanceof Parent) {
            scanAllNodes((Parent) addedNode, pseudoClass);
          }
        }
      }
    }
  }
});

public void removeColorSelectionNode(Node... nodes) {
  colorNodes.removeAll(nodes);
}

public void setContent(Node content) {
  if (contentContainer.getChildren().size() == 2) {
    contentContainer.getChildren().set(1, content);
  } else if (contentContainer.getChildren().size() == 1) {
    contentContainer.getChildren().add(content);
  } else {
    contentContainer.getChildren().setAll(headerSpace, content);
  }
  VBox.setVgrow(content, Priority.ALWAYS);
}

public JFXChip(JFXChipView<T> view, T item) {
  this.view = view;
  getStyleClass().add("jfx-chip");
  setItem(item);
}

private ObservableList<Person> generateDummyData(final int numberOfEntries) {
  final ObservableList<Person> dummyData = FXCollections.observableArrayList();
  for (int i = 0; i < numberOfEntries; i++) {
    dummyData.add(createNewRandomPerson());
  }
  return dummyData;
}

public void setGraphic(Node node) {
  if (graphic != null) {
    graphicContainer.getChildren().remove(graphic);
  }
  if (node != null) {
    graphicContainer.getChildren().add(0, node);
  }
  graphic = node;
}

/**
 * set body node
 *
 * @param body
 */
public void setBody(Node... body) {
  this.body.getChildren().setAll(body);
}

  private void clearAnimation() {
    if (timeline != null) {
      timeline.stop();
      timeline.getKeyFrames().clear();
      timeline = null;
    }
  }
}

/**
 * Constructs a new JFXMasonryPane
 */
public JFXMasonryPane() {
  getChildren().addListener(new WeakListChangeListener<>(childrenListener));
}

  @Override
  public ObservableList<Issue> getIssues() {
    return FXCollections.unmodifiableObservableList(issues);
  }
}

/**
 * Creates empty nodes list.
 */
public JFXNodesList() {
  setPickOnBounds(false);
  getStyleClass().add("jfx-nodes-list");
  setAlignment(Pos.TOP_CENTER);
}

public void addColorSelectionNode(Node... nodes) {
  colorNodes.addAll(nodes);
}

  @Override
  public void onChanged(javafx.collections.ListChangeListener.Change<? extends Node> c) {
    while (c.next()) {
      if (!c.wasPermutated() && !c.wasUpdated()) {
        for (Node addedNode : c.getAddedSubList()) {
          if (addedNode instanceof Parent) {
            scanAllNodes((Parent) addedNode, pseudoClass);
          }
        }
      }
    }
  }
});

/**
 * will change the decorator content
 *
 * @param content
 */
public void setContent(Node content) {
  this.contentPlaceHolder.getChildren().setAll(content);
}

  @Override
  public void dispose() {
    this.control = null;
    if (showTransition != null) {
      showTransition.stop();
      showTransition.getKeyFrames().clear();
      showTransition = null;
    }
  }
}

  protected void initNode(Node node) {
    node.setScaleX(0);
    node.setScaleY(0);
    node.getStyleClass().add("sub-node");
  }
}

public void setValidators(ValidatorBase... validators) {
  this.validators.addAll(validators);
}

/**
 * set actions of the dialog (Accept, Cancel,...)
 *
 * @param actions
 */
public void setActions(Node... actions) {
  this.actions.getChildren().setAll(actions);
}

private void initialize() {
  this.setAutoFix(false);
  this.setAutoHide(true);
  this.setHideOnEscape(true);
  this.setConsumeAutoHidingEvents(false);
  this.getStyleClass().add(DEFAULT_STYLE_CLASS);
}