@Override
    public String toString() {
        return getClass().getSimpleName() + " [Origin: " + origin
                + "  Direction: " + direction + "]";
    }
Returns a string representation of the Line, which is unaffected. For
example, a line with origin (1,0,0) and direction (0,1,0) is represented
by:
<pre>
Line [Origin: (1.0, 0.0, 0.0)  Direction: (0.0, 1.0, 0.0)]
</pre>

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