public RangeOfMotion getJointLimits(String boneName) {
        if (!hasBoneLink(boneName)) {
            String msg = "No linked bone named " + boneName;
            throw new IllegalArgumentException(msg);
        }
        RangeOfMotion result = jointMap.get(boneName);

        assert result != null;
        return result;
    }
Access the nominal range of motion for the joint connecting the named
linked bone to its parent in the hierarchy.

@param boneName the name of the linked bone (not null, not empty)
@return the pre-existing instance (not null)
jme3-jbullet/src/main/java/com/jme3/bullet/animation/DacConfiguration.java