code: def use_tips(self, start_well: Well, num_channels: int = 1):
          
          assert num_channels > 0, 'Bad call to use_tips: num_channels==0'
          # Select the column of the labware that contains the target well
          target_column: List[Well] = [
              col for col in self.columns() if start_well in col][0]
  
          well_idx = target_column.index(start_well)
          # Number of tips to pick up is the lesser of (1) the number of tips
          # from the starting well to the end of the column, and (2) the number
          # of channels of the pipette (so a 4-channel pipette would pick up a
          # max of 4 tips, and picking up from the 2nd-to-bottom well in a
          # column would get a maximum of 2 tips)
          num_tips = min(len(target_column) - well_idx, num_channels)
          target_wells = target_column[well_idx: well_idx + num_tips]
  
          assert all([well.has_tip for well in target_wells]),\
              '{} is out of tips'.format(str(self))
  
          for well in target_wells:
              well.has_tip = False
docs: Removes tips from the tip tracker.
  
          This method should be called when a tip is picked up. Generally, it
          will be called with `num_channels=1` or `num_channels=8` for single-
          and multi-channel respectively. If picking up with more than one
          channel, this method will automatically determine which tips are used
          based on the start well, the number of channels, and the geometry of
          the tiprack.
  
          :param start_well: The :py:class:`.Well` from which to pick up a tip.
                             For a single-channel pipette, this is the well to
                             send the pipette to. For a multi-channel pipette,
                             this is the well to send the back-most nozzle of the
                             pipette to.
          :type start_well: :py:class:`.Well`
          :param num_channels: The number of channels for the current pipette
          :type num_channels: int