See STORY 3 in the linked spec

BDD:

Given that I am viewing a Landing Page (with open drafts) in view mode
When I switch to EDIT MODE,
Then, a modified version of the VERSIONS WIDGET appears,
When I hover over one of my own drafts and click on the EDIT button, 

Then, I enter the EDIT MODE on my draft.
When I click on the PUBLISH BUTTON DROPDOWN,
Then, I see the list of available options.
When I click on SAVE DRAFT,
Then, my draft is saved and a confirmation notification appears.
When I click on the VERSIONS button,
Then, the VERSIONS WIDGET appears,
When I hover over a draft that is not mine and that I don’t have permission to edit,
Then the CAUTION ICON and the VIEW button appears.
When I hover over the caution icon,
Then, a message appears telling me that I don’t have permission to edit the draft.
When I move my cursor off the CAUTION ICON,
Then, the message disappears.
When I hover over a draft I don't have permission to edit and the I click on the VIEW BUTTON that appears,
Then, I am brought to the VIEW MODE of the draft that I have just selected.
When I click on EDIT MODE,
Then, an error notification appears, informing me that I don’t have permission to edit the draft that I am viewing, while I remain in VIEW MODE.