code: def get_channel_names(self):
          
          names_s, names_n = self.channel_names_s, self.channel_names_n
  
          # Figure out which channel names to use
          if self._channel_naming == '$PnS':
              channel_names, channel_names_alternate = names_s, names_n
          else:
              channel_names, channel_names_alternate = names_n, names_s
  
          if len(channel_names) == 0:
              channel_names = channel_names_alternate
  
          if len(set(channel_names)) != len(channel_names):
              msg = (u'The default channel names (defined by the {} '
                     u'parameter in the FCS file) were not unique. To avoid '
                     u'problems in downstream analysis, the channel names '
                     u'have been switched to the alternate channel names '
                     u'defined in the FCS file. To avoid '
                     u'seeing this warning message, explicitly instruct '
                     u'the FCS parser to use the alternate channel names by '
                     u'specifying the channel_naming parameter.')
              msg = msg.format(self._channel_naming)
              warnings.warn(msg)
              channel_names = channel_names_alternate
  
          return channel_names
docs: Get list of channel names. Raises a warning if the names are not unique.