@Override
    public String toString() {
        return getClass().getSimpleName() + " [A: " + a + "  B: " + b + "  C: " + c + "]";
    }
Returns a string representation of the Recatangle, which is unaffected.
For example, a rectangle with vertices at (1,0,0), (2,0,0), (1,2,0), and
(2,2,0) is represented by:
<pre>
Rectangle [A: (1.0, 0.0, 0.0)  B: (2.0, 0.0, 0.0)  C: (1.0, 2.0, 0.0)]
</pre>

@return the string representation (not null, not empty)
jme3-core/src/main/java/com/jme3/math/Rectangle.java