<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _CreatePerformanceTarget(client, campaign_group_id):
 """Creates a performance target for the campaign group. Args: client: an AdWordsClient instance. campaign_group_id: an integer ID for the campaign group. """

  # Get the CampaignGroupPerformanceTargetService.
  cgpt_service = client.GetService('CampaignGroupPerformanceTargetService',
                                   version='v201809')

  # Create the operation.
  operations = [{
      'operator': 'ADD',
      # Create the performance target.
      'operand': {
          'campaignGroupId': campaign_group_id,
          'performanceTarget': {
              # Keep the CPC for the campaigns < $3.
              'efficiencyTargetType': 'CPC_LESS_THAN_OR_EQUAL_TO',
              'efficiencyTargetValue': 3000000,
              # Keep the maximum spend under $50.
              'spendTargetType': 'MAXIMUM',
              'spendTarget': {
                  'microAmount': 500000000
              },
              # Aim for at least 3000 clicks.
              'volumeGoalType': 'MAXIMIZE_CLICKS',
              'volumeTargetValue': 3000,
              # Start the performance target today, and run it for the next 90
              # days.
              'startDate': datetime.datetime.now().strftime('%Y%m%d'),
              'endDate': (datetime.datetime.now() +
                          datetime.timedelta(90)).strftime('%Y%m%d')
          }
      }
  }]

  cgpt = cgpt_service.mutate(operations)['value'][0]

  # Display the results.
  print ('Campaign performance target with ID "%d" was added for campaign '
         'group ID "%d".' % (cgpt['id'], cgpt['campaignGroupId']))