def obs_item
import bend-collections@1.0.0.0/src/containers/stack.bend as Stackimport Base
import bend-collections@1.0.0.0/src/containers/types/stack.bend as E
44def obs_item(~T: Data, r: Stack<T> & Result<&2, &2, E.Error, T>) -> Stack<T> & E.Obs<T>:
45 (q, x) = r
46 (q, E.OItem{x})