Adding tests for these parts of the API which are pretty stable will increase coverage:

GraphicFeatures

• Alpha
• AlphaMode

PlotArea

• @camera.setter, replacing the camera
• get and set background_color
• remove_animation
• add_graphic, when adding back a graphic that was removed from the scene
• insert_graphic
• delete_graphic, maybe combine with garbage collection?
• clear
• __contains__

Graphic

• alpha
• alpha_mode
• deleted, maybe test the event, need to think
• event_handlers list
• clear_event_handlers
• _fpl_prepare_del, need to think about this one, check that all the event handlers are cleared etc and the object gets garbage collected?
• rotate

Figure

• names
• add_animations
• remove_animation
• clear

HistogramLUTTool

• generally needs a lot of tests, can do once this API and functionality is much better

Layout engine

• generally needs a lot of backend tests, can do once API solidified and add/remove subplots is functional