# File lib/linecache.rb, line 291
  def unmap_file_line(file, line)
    if @@file2file_remap_lines[file]
      @@file2file_remap_lines[file].each do |from_file, range, start|
        if range === line
          from_file = from_file || file 
          return [from_file, start+line-range.begin] 
        end
      end
    end
    return [file, line]
  end