Find illegal use of private members

[davidhesselbom]

Find usage of other classes' private functions and variables, for instance

Foo: class {
    _x: Int
    init: func
}
foo := Foo new()
foo _x = 1 // bad, only Foo instances themselves should have immediate access to _x

[davidpiuva]

Preventing use files from showing private members would allow other classes in the same framework (mostly regression tests) to have private access while hiding it to basic callers. Import declarations will then have full access in case you need it.