def partially_loaded?(offset, limit = 1)
      if offset >= 0
        lazy_possible?(head, offset + limit)
      else
        lazy_possible?(tail, offset.abs)
      end
    end
def partially_loaded?(offset, limit = 1)
      if offset >= 0
        lazy_possible?(head, offset + limit)
      else
        lazy_possible?(tail, offset.abs)
      end
    end
Test if the collection is loaded between the offset and limit

 @param [Integer] offset
   the offset of the collection to test
 @param [Integer] limit
   optional limit for how many entries to be loaded

 @return [Boolean]
   true if the collection is loaded from the offset to the limit

 @api private