    linkView.addTools(toolsView)

Add the provided `toolsView` (of the `joint.dia.ToolsView` type) to the link view.

Adding a tools view to a link view is the last (third) step in the process of setting up link tools on a link view:

    // 1) creating link tools
    var verticesTool = new joint.linkTools.Vertices();
    var segmentsTool = new joint.linkTools.Segments();
    var boundaryTool = new joint.linkTools.Boundary();

    // 2) creating a tools view
    var toolsView = new joint.dia.ToolsView({
        name: 'basic-tools',
        tools: [verticesTool, segmentsTool, boundaryTool]
    });

    // 3) attaching to a link view
    var linkView = link.findView(paper);
    linkView.addTools(toolsView);

Every link view we want to attach to requires its own tools view object (`ToolsView` objects are automatically reassigned to the last link view they are added to). Similarly, every tools view we create requires its own set of tools (`ToolView` objects are automatically reassigned to the last `toolsView.tools` array they were made part of).

The link tools are added in the visible state. Use the `linkView.hideTools` function if this behavior is not desirable (e.g. if you want the link tools to appear in response to user interaction). Example:

    linkView.addTools(toolsView);
    linkView.hideTools();

    paper.on('link:mouseenter', function(linkView) {
        linkView.showTools();
    });

    paper.on('link:mouseleave', function(linkView) {
        linkView.hideTools();
    });