JSTests/stress/private-methods-megamorphic-ic.js

function assert(actual, expected) {
    if (actual !== expected)
        throw Error("Expected: " + expected + " Actual: " + actual);
}

function classExpr() {
    return class {
        #method() {
            return 'foo';
        }

        access() {
           return this.#method();
        }
    }
}

for (let i = 0; i < 10000; i++) {
    let C = classExpr();
    let c = new C();
    assert(c.access(), 'foo');
}