`internal(set)` in `Messages.swift` makes it impossible to initialize PixelMessage objects.

[WolfLink]

The inclusion of internal(set) for type on the PixelMessage objects makes the default initializer internal, making it impossible to initialize PixelMessage objects in order to use parts of the API such as sendMessage, and in general making this version of the API much weaker than the others.

[WolfLink]

This simplest fix is to remove internal from all of the type properties. A more in-depth solution would be to define public initializers.