public float getMinNurbKnot() {
        return knots.get(basisFunctionDegree - 1);
    }
This method returns the minimum nurb curve knot value. Check the nurb
type before calling this method. If the curve is not of a Nurb type, an NPE
will be thrown.

@return the minimum nurb curve knot value
jme3-core/src/main/java/com/jme3/math/Spline.java