Method clone

packages/common/http/src/headers.ts:201–206

(update: Update)

  }

  private clone(update: Update): HttpHeaders {
    const clone = new HttpHeaders();
    clone.lazyInit = !!this.lazyInit && this.lazyInit instanceof HttpHeaders ? this.lazyInit : this;
    clone.lazyUpdate = (this.lazyUpdate || []).concat([update]);
    return clone;
  }

  private applyUpdate(update: Update): void {
    const key = update.name.toLowerCase();