def __init__(self, charlist , variable_name=''):
   """
   AtomicPulse_Event(output_mask, duration):
     output_mask = mask used to generate pulse output
     duration = duration of output
   """
   Event.__init__(self)
   self.charlist        = charlist
   self.variable_name   = variable_name
 def __init__(self, output_mask, duration = 0x00, is_min_duration = False):
   """
   AtomicPulse_Event(output_mask, duration):
     output_mask = mask used to generate pulse output
     duration = duration of output
   """
   Event.__init__(self)
   if (not output_mask.is_output_mask()):
     raise RuntimeError("Given input is not an output mask.")
   if (is_min_duration and (duration != 0x00)):
     raise RuntimeError("Cannot specify both is_min_duration and duration.")
   self.output_mask     = output_mask
   self.duration        = duration
   self.is_min_duration = is_min_duration