code: @Deprecated
    public void setClassesDir(File classesDir) {
      if (classesDir == null) throw new NullPointerException("classesDir");
      getLogger().warn("The 'classesDir' property on the '{}' task is deprecated. Use 'classesDirs' of type FileCollection instead!",
          getName());
      setClassesDirs(getProject().files(classesDir));
    }
docs: Sets the directory where to look for classes. Overwrites any value set by {@link #setClassesDirs(FileCollection)}!
  @deprecated use {@link #setClassesDirs(FileCollection)} instead.
  @see #getClassesDir