stashedFiles.add(new StashedFile(fileToDelete, stashedFile));
        }
        return stashedFiles;
    }

    private void deleteEmptyDirectoriesAfterCompilation(List<StashedFile> stashedFiles) {
        ImmutableSet<File> outputDirectories = getOutputDirectories();
        Set<File> potentiallyEmptyFolders = stashedFiles.stream()
            .map(file -> file.sourceFile.getParentFile())

Class <org.gradle.api.internal.tasks.compile.incremental.transaction.CompileTransaction$StashedFile> is not annotated (directly or via its package) with @org.gradle.api.NonNullApi in (CompileTransaction.java:0)