Function mirrorProperties

test/helpers/sinon.js:662–668

(target, source)

    }

    function mirrorProperties(target, source) {
        for (var prop in source) {
            if (!hasOwn.call(target, prop)) {
                target[prop] = source[prop];
            }
        }
    }

    function isRestorable (obj) {
        return typeof obj === "function" && typeof obj.restore === "function" && obj.restore.sinon;