code: public ListCollectionsResult withFaceModelVersions(String... faceModelVersions) {
          if (this.faceModelVersions == null) {
              setFaceModelVersions(new java.util.ArrayList<String>(faceModelVersions.length));
          }
          for (String ele : faceModelVersions) {
              this.faceModelVersions.add(ele);
          }
          return this;
      }
docs: <p>
  Version numbers of the face detection models associated with the collections in the array
  <code>CollectionIds</code>. For example, the value of <code>FaceModelVersions[2]</code> is the version number for
  the face detection model used by the collection in <code>CollectionId[2]</code>.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setFaceModelVersions(java.util.Collection)} or {@link #withFaceModelVersions(java.util.Collection)} if
  you want to override the existing values.
  </p>
  
  @param faceModelVersions
  Version numbers of the face detection models associated with the collections in the array
  <code>CollectionIds</code>. For example, the value of <code>FaceModelVersions[2]</code> is the version
  number for the face detection model used by the collection in <code>CollectionId[2]</code>.
  @return Returns a reference to this object so that method calls can be chained together.