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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def GetAdGroups(self, client_customer_id, campaign_id):
 """Retrieves all AdGroups for the given campaign that haven't been removed. Args: client_customer_id: str Client Customer Id being used in API request. campaign_id: str id of the campaign for which to fetch ad groups. Returns: list List of AdGroup data objects. """

    self.client.SetClientCustomerId(client_customer_id)
    selector = {
        'fields': ['Id', 'Name', 'Status'],
        'predicates': [
            {
                'field': 'CampaignId',
                'operator': 'EQUALS',
                'values': [campaign_id]
            },
            {
                'field': 'Status',
                'operator': 'NOT_EQUALS',
                'values': ['REMOVED']
            }
        ]
    }
    adgroups = self.client.GetService('AdGroupService').get(selector)

    if int(adgroups['totalNumEntries']) > 0:
      return adgroups['entries']
    else:
      return None