[enh] setattr slice@lower
[enh] setattr slice@lower none
[enh] setattr slice@upper
[enh] setattr slice@upper none
[enh] setattr slice@step
[enh] setattr slice@step none
[enh] setattr ternary_operator@first
[enh] setattr ternary_operator@second
[enh] setattr ternary_operator@value
[mod] update TODO
[enh] setattr unitary_operator@target
[enh] setattr yield@value
[enh] setattr yield@value none
[enh] setattr yield@value was none
[enh] setattr yield_atom@value/none/was none