code: def allZero(buffer):
      
      allZero = True
      for byte in buffer:
          if byte != "\x00":
              allZero = False
              break
      return allZero
docs: Tries to determine if a buffer is empty.
      
      @type buffer: str
      @param buffer: Buffer to test if it is empty.
          
      @rtype: bool
      @return: C{True} if the given buffer is empty, i.e. full of zeros,
          C{False} if it doesn't.