Fix #354. Clarify return value of lifted generator in example
Fix #354. Clarify return value of lifted generator in example

caporta/when,petkaantonov/when,stevage/when,tkirda/when,tkirda/when,mlennon3/when,SourcePointUSA/when,caporta/when,anthonyvia/when,anthonyvia/when,SourcePointUSA/when,frank-weindel/when,mlennon3/when,ning-github/when,frank-weindel/when,ning-github/when,stevage/when