code: def _get_by_id(collection, id):
      '''
      Get item from a list by the id field
      '''
      matches = [item for item in collection if item.id == id]
      if not matches:
          raise ValueError('Could not find a matching item')
      elif len(matches) > 1:
          raise ValueError('The id matched {0} items, not 1'.format(len(matches)))
      return matches[0f _get_by_id(collection, id):
      '''
      Get item from a list by the id field
      '''
      matches = [item for item in collection if item.id == id]
      if not matches:
          raise ValueError('Could not find a matching item')
      elif len(matches) > 1:
          raise ValueError('The id matched {0} items, not 1'.format(len(matches)))
      return matches[0]
docs: Get item from a list by the id field