code: public void removeConstraint(final GVRConstraint gvrConstraint) {
          mPhysicsContext.runOnPhysicsThread(new Runnable() {
              @Override
              public void run() {
                  if (contains(gvrConstraint)) {
                      NativePhysics3DWorld.removeConstraint(getNative(), gvrConstraint.getNative());
                      mPhysicsObject.remove(gvrConstraint.getNative());
                  }
              }
          });
      }
docs: Remove a {@link GVRFixedConstraint} from this physics world.
  
  @param gvrConstraint the {@link GVRFixedConstraint} to remove.