def sequential(value)
      index = index_variable_for(value)
      index = (index ? index + 1 : 0)
      index = 0 if index == value.length
      set_index_variable(value, index)
      value[index]
    end
def sequential(value)
      index = index_variable_for(value)
      index = (index ? index + 1 : 0)
      index = 0 if index == value.length
      set_index_variable(value, index)
      value[index]
    end
return an element from the array.  The first request will return
 the first element, the second request will return the second,
 and so forth.