How to use the oauth.OAuth2.prototype function in oauth

OAuth2CA.prototype._executeRequest  = function(http_library, options, post_body, callback) {
    options.rejectUnauthorized = this.options.rejectUnauthorized == null ?
        true : this.options.rejectUnauthorized;
    if (this.options.basicAuth) {
        options.auth = this.options.basicAuth;
    }
    OAuth2.prototype._executeRequest.call(
        this, http_library, options, post_body, callback)
}