in maven-plugin-testing-harness/src/main/java/org/apache/maven/api/plugin/testing/MojoExtension.java [648:654]
public static void setVariableValueToObject(Object object, String variable, Object value)
throws IllegalAccessException {
Field field = ReflectionUtils.getFieldByNameIncludingSuperclasses(variable, object.getClass());
requireNonNull(field, "Field " + variable + " not found");
field.setAccessible(true);
field.set(object, value);
}