export default function StringBuilder(...strs: any[]): {
    append(...strsa: any[]): any;
    toString(): string;
    length(): number;
    charAt(idx: any): string;
    setCharAt(idx: any, ch: any): any;
    replace(start: any, end: any, str: any): any;
    codePointAt(at: any): number | undefined;
    delete(from: any, to: any): any;
};