Boolean expression parsing does not recognize the use of a simple boolean

Assume there is a class “A”, with a boolean attribute “success”.

It is currently not possible to type “success” when a boolean expression is required. For example, if one creates a method + void m() for class A, and then creates an “opt” fragment in the sequence diagram, then it should be possible to use as a condition simply “success”. That is not possible currently. Currently one must type “success == true”.