code: def compare_with_existing(self, region='us-east-1', onetime=False):
          
          pipelines = self.get_existing_pipelines()
          pipeline_id = None
          found = False
          for pipeline in pipelines:
              correct_app_and_region = (pipeline['application'] == self.app_name) and (region in pipeline['name'])
              if onetime:
                  onetime_str = "(onetime-{})".format(self.environments[0])
                  if correct_app_and_region and onetime_str in pipeline['name']:
                      found = True
              elif correct_app_and_region:
                  found = True
  
              if found:
                  self.log.info('Existing pipeline found - %s', pipeline['name'])
                  pipeline_id = pipeline['id']
                  break
          else:
              self.log.info('No existing pipeline found')
  
          return pipeline_id
docs: Compare desired pipeline with existing pipelines.
  
          Args:
              region (str): Region of desired pipeline.
              onetime (bool): Looks for different pipeline if Onetime
  
          Returns:
              str: pipeline_id if existing, empty string of not.