private void extendNumber(Class clazz) {
        ExpandoMetaClass expando = new ExpandoMetaClass(clazz, true, false);
        expando.registerInstanceMethod("plus", new NumberClosure(this, (n, s) -> s.plus(n)));
        expando.registerInstanceMethod("minus", new NumberClosure(this, (n, s) -> s.minus(n).negative()));
        expando.registerInstanceMethod("multiply", new NumberClosure(this, (n, s) -> s.multiply(n)));
        expando.registerInstanceMethod("div", new NumberClosure(this, (n, s) -> s.newValue(v -> n.doubleValue() / v)));
        expando.initialize();
    }
Run the expression with a data map.

@param sampleFamilies a data map includes all of candidates to be analysis.
@return The result of execution.
oap-server/analyzer/meter-analyzer/src/main/java/org/apache/skywalking/oap/meter/analyzer/dsl/Expression.java