add a unit test for stream execute comments
add a unit test for stream execute comments

Signed-off-by: Arka Ganguli <39edf440a7a1cf1852f08299863318eb3c90f59e@gmail.com>

vitessio/vitess,tinyspeck/vitess,tinyspeck/vitess,tinyspeck/vitess,tinyspeck/vitess,mahak/vitess,mahak/vitess,vitessio/vitess,mahak/vitess,mahak/vitess,tinyspeck/vitess,vitessio/vitess,mahak/vitess,vitessio/vitess,mahak/vitess,mahak/vitess,vitessio/vitess,mahak/vitess,tinyspeck/vitess,tinyspeck/vitess,vitessio/vitess,vitessio/vitess,vitessio/vitess