Has anyone designed an L shaped bar seating area in a kitchen with "expansion"?

[jcpsmallwoodworkershop]

Has anyone designed an L shaped bar seating area in a kitchen with "expansion"?

i am asked to design a L shaped bar in a kitchen seating area and the top of the L bar
is cantilevered out so there is room to fit bar stools under. then the question came up
since the top of the bar is empty below, can a half moon round extension be custom
designed in around a pivot at the corner and remain hidden until needed, and when
needed spin around underneath and pop up to provide a round bar table at the
corner of the L?
anyone every try this? anyone pointers to hardware manufacturers of the pivot and
pop out?

thanks