code: def set_speed(self, aspirate=None, dispense=None):
          
          if aspirate:
              self.speeds['aspirate'] = aspirate
          if dispense:
              self.speeds['dispense'] = dispense
          return self
docs: Set the speed (mm/second) the :any:`Pipette` plunger will move
          during :meth:`aspirate` and :meth:`dispense`
  
          Parameters
          ----------
          aspirate: int
              The speed in millimeters-per-second, at which the plunger will
              move while performing an aspirate
  
          dispense: int
              The speed in millimeters-per-second, at which the plunger will
              move while performing an dispense