title: How to make TreeView resize as much as parent ScrollPane is?
body: <p>I have TreeView placed as content of ScrollPane. ScrollPane is placed inside SplitPane. 
  When I drag divider of SplitPane so that it becomes bigger than TreeView size I see border of TreeView.
  I want TreeView to be resized as much as space is available after I drag divider of SplitPane. My code:</p>
  
  <pre><code>SplitPane splitPane = new SplitPane();
  splitPane.getItems().addAll(createTreeOfConnections());
  
  private ScrollPane createTreeOfConnections() {
  ScrollPane scrollPane = new ScrollPane();
  scrollPane.setMinSize(100, 300);
  scrollPane.setPrefSize(200, 500);
      scrollPane.setMaxSize(Double.MAX_VALUE, Double.MAX_VALUE);
  scrollPane.setVbarPolicy(ScrollBarPolicy.AS_NEEDED);
  scrollPane.setHbarPolicy(ScrollBarPolicy.AS_NEEDED);
  scrollPane.setContent(new ConnectionsTree(this));
  return scrollPane;
  </code></pre>
  
  <p>Class ConnectionsTree extends TreeView and its constructor is :</p>
  
  <pre><code>public ConnectionsTree(MainStage mainStage) {
          // here we set the root of ConnectionsTree which is not visible
          super();
          this.mainStage = mainStage;
  
          root = new ConnectionTreeItem();
          root.setExpanded(true);
          super.setRoot(root);
          super.setShowRoot(false);
          super.setEditable(false);
          super.getSelectionModel().setSelectionMode(SelectionMode.SINGLE);
          super.setMaxSize(Double.MAX_VALUE, Double.MAX_VALUE);
  
          retrieveExistentConnectionsNodes();
          ContextMenu contextMenu = new ContextMenu(createNewConnectionMenuItem(
                  "New Connection", KeyCombination.valueOf("Ctrl+N")));
          super.setContextMenu(contextMenu);                }
  </code></pre>
  
  <p>How to tell TreeView(my TreeConnections) that it should take all available space of left part of SplitPane?</p>
  
  <p>Thank you!</p>