Method removeUnusedKeyframes

packages/purgecss/src/index.ts:870–879

* Remove unused keyframes

()

   * Remove unused keyframes
   */
  public removeUnusedKeyframes(): void {
    for (const node of this.atRules.keyframes) {
      if (
        !this.usedAnimations.has(node.params) &&
        !this.isKeyframesSafelisted(node.params)
      ) {
        node.remove();
      }
    }
  }

  /**
   * Transform a selector node into a string