public NumberExpression<Double> m() {
        if (m == null) {
            m = Expressions.numberOperation(Double.class, SpatialOps.M, mixin);
        }
        return m;
    }
The m-coordinate value for this Point, if it has one. Returns NIL otherwise.

@return m-coordinate
querydsl-spatial/src/main/java/com/querydsl/spatial/jts/JTSPointExpression.java