Assert an accordion panel is (or is not) open: its header button carries aria-expanded="true" and its body is visible.
Examples
Then the "Media Left" accordion panel should be open
And the "Media Right" accordion panel should not be open
Then the "No Media" accordion panel should be open
And the "Media Top" accordion panel should not be open
Then the "Media Bottom" accordion panel should not be open
Pattern
Then(/^the "([^"]*)?" accordion panel should( not)* be open$/, …)
Part of @webship-js/typo3-steps (github.com/webship/typo3-steps), a step pack for Webship-js 2.0.x.