def get_ad_groups_by_campaign_id(campaign_id)
			response = call(:get_ad_groups_by_campaign_id, 
				{campaign_id: campaign_id})
			response_hash = get_response_hash(response, __method__)
			ad_groups = response_hash[:ad_groups][:ad_group].map do |ad_group_hash|
				BingAdsApi::AdGroup.new(ad_group_hash)
			end
			return ad_groups
		end
def get_ad_groups_by_campaign_id(campaign_id)
			response = call(:get_ad_groups_by_campaign_id, 
				{campaign_id: campaign_id})
			response_hash = get_response_hash(response, __method__)
			ad_groups = response_hash[:ad_groups][:ad_group].map do |ad_group_hash|
				BingAdsApi::AdGroup.new(ad_group_hash)
			end
			return ad_groups
		end
Public : Returns all the ad groups that belongs to the
 specified campaign

 Author:: jlopezn@neonline.cl

 === Parameters
 campaign_id   - campaign id

 === Examples
   service.get_ad_groups_by_campaign_id(1)
   # => Array[AdGroups]

 Returns:: Array with all the ad groups present in campaign_id

 Raises:: exception