Potential gap in documentation for using cucumber with nightwatch

[ctbaird]

The nightwatch example for Cucumber js includes return statements before all browser commands, e.g.
return browser.assert.titleEquals(title); See the example here.

In practice, omitting the return statement before browser.assert (and maybe others) leads to unexpected behavior, like tests passing when assertions fail. However, this does not seem to be specified in the nightwatch documentation for using Cucumber with nighwatch, or for Assertions.

This is confusing because the syntax differs from that in the Cucumber documentation.

Why is the return necessary?