this is a url: http://www.example.com/foo-bar
 key   0:13  ^-----------^                                  this is a url
 url  15:45                 ^----------------------------^  http://www.example.com/foo-bar
 val  15:45                 ^----------------------------^  http://www.example.com/foo-bar
pair   0:45  ^-------------------------------------------^  this is a url: http://www.example.com/foo-bar
msg         :this is a url: http://www.example.com/foo-bar
format      :this is a url: #
{
    "this is a url": "http://www.example.com/foo-bar"
}