new_contents: BCM = 0
  BOARD = 1
  
  OUT = 0
  IN = 1
  
  PUD_UP = 0
  PUD_DOWN = 1
  
  
  def setmode(mode):
      pass
  
  
  def setup(pin, mode, pull_up_down=None):
      pass
  
  
  def input(pin):
      pass
  
  
  def output(pin, state):
      pass
  
  
  def add_interrupt_callback(pin, mode, debounce_timeout_ms=0):
      pass
  
  
  def wait_for_interrupts(threaded):
      pass
  
subject: Add a shell RPIO package to facilitate testing.