code: def _set_flow_rate(
          pipette_name, pipette, command_type, params, default_values):
      
      default_aspirate = default_values.get(
          'aspirate-flow-rate', {}).get(pipette_name)
  
      default_dispense = default_values.get(
          'dispense-flow-rate', {}).get(pipette_name)
  
      flow_rate_param = params.get('flow-rate')
  
      if flow_rate_param is not None:
          if command_type == 'aspirate':
              pipette.flow_rate = {
                  'aspirate': flow_rate_param,
                  'dispense': default_dispense
              }
              return
          if command_type == 'dispense':
              pipette.flow_rate = {
                  'aspirate': default_aspirate,
                  'dispense': flow_rate_param
              }
              return
  
      pipette.flow_rate = {
          'aspirate': default_aspirate,
          'dispense': default_dispense
      }
docs: Set flow rate in uL/mm, to value obtained from command's params,
      or if unspecified in command params, then from protocol's "default-values".