code: def set_clock_type(type):
      
      type = type.upper()
      if type not in CLOCK_TYPES:
          raise YappiError("Invalid clock type:%s" % (type))
          
      _yappi.set_clock_type(CLOCK_TYPES[type])
docs: Sets the internal clock type for timing. Profiler shall not have any previous stats.
      Otherwise an exception is thrown.