findAllIncubating()
                .map { node -> toVersionIncubating(sourceFile, node) }
                .forEach { (version, incubating) ->
                    versionsToIncubating.getOrPut(version) { mutableSetOf() }.add(incubating)
                }
        }
        return versionsToIncubating
    }

    private
    fun CompilationUnit.findAllIncubating() =
        findAll(Node::class.java).filter { it.isIncubating }