def check_for_resize
      while (current_table = table) && MAX_CAPACITY > (table_size = current_table.size) && NOW_RESIZING != (size_ctrl = size_control) && size_ctrl < @counter.sum
        try_in_resize_lock(current_table, size_ctrl) do
          self.table = rebuild(current_table)
          (table_size << 1) - (table_size >> 1) # 75% load factor
        end
      end
    end
def check_for_resize
      while (current_table = table) && MAX_CAPACITY > (table_size = current_table.size) && NOW_RESIZING != (size_ctrl = size_control) && size_ctrl < @counter.sum
        try_in_resize_lock(current_table, size_ctrl) do
          self.table = rebuild(current_table)
          (table_size << 1) - (table_size >> 1) # 75% load factor
        end
      end
    end
If table is too small and not already resizing, creates next table and
 transfers bins. Rechecks occupancy after a transfer to see if another
 resize is already needed because resizings are lagging additions.