Assert a region of the layout in the editor has (or does not have) a block, by the title the editor shows.
Examples
Then the "Sidebar" region should have the "Syndicate" block
Then the "Sidebar" region should not have the "Syndicate" block
And the "Header" region should have the "Search form" block
Then the "Footer" region should have the "Feeds" block
And the "Content" region should have the "Main page content" block
Pattern
Then(/^the "([^"]*)" region should( not)* have the "([^"]*)" block$/, …)
Part of @webship-js/backdrop-cms-steps (github.com/webship/backdrop-cms-steps), a step pack for Webship-js 2.0.x.