def group(*args, &block)
    raise ArgumentError, "no block given" unless block

    `#@native.group.apply(#@native, args)`

    begin
      if block.arity == 0
        instance_exec(&block)
      else
        block.call(self)
      end
    ensure
      `#@native.groupEnd()`
    end
  end
def group(*args, &block)
    raise ArgumentError, "no block given" unless block

    `#@native.group.apply(#@native, args)`

    begin
      if block.arity == 0
        instance_exec(&block)
      else
        block.call(self)
      end
    ensure
      `#@native.groupEnd()`
    end
  end
Group the given block.