code: function() {
      let addon = this._findCoveredAddon();
      if (addon) {
        const addonDir = path.join(this.project.root, 'addon');
        const addonTestSupportDir = path.join(this.project.root, 'addon-test-support');
        return concat(
          this._getIncludesForDir(addonDir, addon.name),
          this._getIncludesForDir(addonTestSupportDir, `${addon.name}/test-support`)
        );
      }
    }
docs: Get paths to include for covering the "addon" directory.
  @returns {Array<String>} include paths