text: #!/usr/bin/python
  """tests for panel button function
  
  :author: `Patrick Kanzler <patrick.kanzler@fablab.fau.de>`_
  :organization: `python-escpos <https://github.com/python-escpos>`_
  :copyright: Copyright (c) 2016 `python-escpos <https://github.com/python-escpos>`_
  :license: GNU GPL v3
  """
  
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  
  from nose.tools import with_setup
  
  import escpos.printer as printer
  import os
  
  devfile = 'testfile'
  
  
  def setup_testfile():
      """create a testfile as devfile"""
      fhandle = open(devfile, 'a')
      try:
          os.utime(devfile, None)
      finally:
          fhandle.close()
  
  
  def teardown_testfile():
      """destroy testfile again"""
      os.remove(devfile)
  
  
  @with_setup(setup_testfile, teardown_testfile)
  def test_function_panel_button_on():
      """test the panel button function (enabling) by comparing output"""
      instance = printer.File(devfile=devfile)
      instance.panel_buttons()
      instance.flush()
      with open(devfile, "rb") as f:
          assert(f.read() == b'\x1B\x63\x35\x00')
  
  
  @with_setup(setup_testfile, teardown_testfile)
  def test_function_panel_button_off():
      """test the panel button function (disabling) by comparing output"""
      instance = printer.File(devfile=devfile)
      instance.panel_buttons(False)
      instance.flush()
      with open(devfile, "rb") as f:
          assert(f.read() == b'\x1B\x63\x35\x01')
  