Containers

operator			operand
expression	function	type	method	type
`len(_)`	`do_len`	`DoesLen`	`__len__`	`CanLen`
`_.__length_hint__()` (docs)	`do_length_hint`	`DoesLengthHint`	`__length_hint__`	`CanLengthHint`
`_[k]`	`do_getitem`	`DoesGetitem`	`__getitem__`	`CanGetitem[-K, +V]`
`_.__missing__()` (docs)	`do_missing`	`DoesMissing`	`__missing__`	`CanMissing[-K, +D]`
`_[k] = v`	`do_setitem`	`DoesSetitem`	`__setitem__`	`CanSetitem[-K, -V]`
`del _[k]`	`do_delitem`	`DoesDelitem`	`__delitem__`	`CanDelitem[-K]`
`k in _`	`do_contains`	`DoesContains`	`__contains__`	`CanContains[-K=object]`
`reversed(_)`	`do_reversed`	`DoesReversed`	`__reversed__`	`CanReversed[+R]`, or `CanSequence[-I, +V]`

Because CanMissing[K, D] generally doesn't show itself without CanGetitem[K, V] there to hold its hand, optype conveniently stitched them together as optype.CanGetMissing[K, V, D=V].

Similarly, there is optype.CanSequence[K: CanIndex | slice, V], which is the combination of both CanLen and CanItem[I, V], and serves as a more specific and flexible collections.abc.Sequence[V].