code: def rank(self, value):
          '''The rank of a given *value*. This is the position of *value*
  in the :class:`OrderedMixin` container.'''
          value = self.value_pickler.dumps(value)
          return self.backend_structure().rank(valuef rank(self, value):
          '''The rank of a given *value*. This is the position of *value*
  in the :class:`OrderedMixin` container.'''
          value = self.value_pickler.dumps(value)
          return self.backend_structure().rank(value)
docs: The rank of a given *value*. This is the position of *value*
  in the :class:`OrderedMixin` container.