code: public GVRSkeleton createSkeleton(List<String> boneNames)
      {
          int numBones = boneNames.size();
          GVRSceneObject root = (GVRSceneObject) mTarget;
          mSkeleton = new GVRSkeleton(root, boneNames);
          for (int boneId = 0; boneId < numBones; ++boneId)
          {
              mSkeleton.setBoneOptions(boneId, GVRSkeleton.BONE_ANIMATE);
          }
          mBoneChannels = new GVRAnimationChannel[numBones];
          return mSkeleton;
      }
docs: Create a skeleton from the target hierarchy which has the given bones.
  <p>
  The structure of the target hierarchy is used to determine bone parentage.
  The skeleton will have only the bones designated in the list.
  The hierarchy is expected to be connected with no gaps or unnamed nodes.
  @param boneNames names of bones in the skeleton.
  @return {@link GVRSkeleton} created from the target hierarchy.