Method append

sdk/js/src/core/fetcher/Headers.ts:39–43

(name: string, value: string)

        }

        append(name: string, value: string): void {
            const key = name.toLowerCase();
            const existing = this.headers.get(key) || [];
            this.headers.set(key, [...existing, value]);
        }

        delete(name: string): void {
            const key = name.toLowerCase();