code: def lastIndexOf(self, item):
          
          array = self.obj
          i = len(array) - 1
          if not (self._clean.isList() or self._clean.isTuple()):
              return self._wrap(-1)
  
          while i > -1:
              if array[i] is item:
                  return self._wrap(i)
              i -= 1
          return self._wrap(-1)
docs: Return the position of the last occurrence of an
          item in an array, or -1 if the item is not included in the array.