code: function addFunctionVendor (task, name) {
          tasks.addTask({
              forBrowsersLowerThan: task.browsers,
              filter: 'Declaration',
              fn: function (declaration) {
                  if (declaration.has({
                      type: 'Function',
                      vendor: false,
                      name: name
                  })) {
                      declaration
                          .cloneBefore()
                          .getAll({
                              type: 'Function',
                              name: name
                          })
                          .forEach(fn => fn.setVendor(task.vendor));
                  }
              }
          });
      }
docs: HELPERS FUNCTIONS