supportedFunctions() {
        const supported = [];
        const functions = Object.keys(this.functions);
        functions.forEach(fun => {
            try {
                const res = this.functions[fun](0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
                if (res === undefined) return;
                supported.push(fun);
            } catch (e) {
                if (e instanceof Error)
                    supported.push(fun);
            }
        });
        return supported.sort();
    }
Return currently supported functions.
@return {this}