code: public DetectFacesResult withFaceDetails(FaceDetail... faceDetails) {
          if (this.faceDetails == null) {
              setFaceDetails(new java.util.ArrayList<FaceDetail>(faceDetails.length));
          }
          for (FaceDetail ele : faceDetails) {
              this.faceDetails.add(ele);
          }
          return this;
      }
docs: <p>
  Details of each face found in the image.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setFaceDetails(java.util.Collection)} or {@link #withFaceDetails(java.util.Collection)} if you want to
  override the existing values.
  </p>
  
  @param faceDetails
  Details of each face found in the image.
  @return Returns a reference to this object so that method calls can be chained together.