func(arg1="a", arg2="b")
key 5:5 ^
key 5:9 ^--^ arg1
quot 11:12 ^ a
val 11:12 ^ a
pair 5:12 ^-----^ arg1="a
key 15:19 ^--^ arg2
quot 21:22 ^ b
val 21:22 ^ b
pair 15:22 ^-----^ arg2="b
grp 5:22 ^---------------^ arg1="a", arg2="b
pair 5:22 ^---------------^ arg1="a", arg2="b