addonLintTree(type, tree) {
    let output = lintAddonsByType(this.project.addons, type, tree);

    return mergeTrees(output, {
      overwrite: true,
      annotation: `TreeMerger (lint ${type})`,
    });
  }
Runs addon lintTree hooks and returns a single tree containing all
    their output.

    @private
    @method addonLintTree
    @param  {String} type Type of tree
    @param  {Tree}   tree Tree to process
    @return {Tree}        Processed tree