kickoff_duration=4.41074371338e-05
 key   0:16  ^--------------^                    kickoff_duration
 num  17:34                   ^---------------^  4.41074371338e-05
 val  17:34                   ^---------------^  4.41074371338e-05
pair   0:34  ^--------------------------------^  kickoff_duration=4.41074371338e-05