public void addTestCompileSourceRoot()

in maven-plugin-testing-harness/src/main/java/org/apache/maven/plugin/testing/stubs/MavenProjectStub.java [346:352]


    public void addTestCompileSourceRoot(String string) {
        if (testCompileSourceRoots == null) {
            testCompileSourceRoots = new ArrayList<>(Collections.singletonList(string));
        } else {
            testCompileSourceRoots.add(string);
        }
    }