text: from policyuniverse.common import Sequence
  from policyuniverse.statement import Mapping
  
  
  class CustomSequence(Sequence):
      def __init__(self, data):
          self._sequence = data
  
      def __getitem__(self, item):
          return self._sequence[item]
  
      def __len__(self):
          return len(self._sequence)
  
  
  class CustomMapping(Mapping):
      def __init__(self, data):
          self._mapping = data
  
      def __getitem__(self, item):
          return self._mapping[item]
  
      def __len__(self):
          return len(self._mapping)
  
      def __iter__(self):
          return iter(self._mapping)
  