isString(pattern)
                ? splitPattern(pattern)
                : pattern
        ).forEach(this._addPattern, this)

        // Some rules have just added to the ignore,
        // making the behavior changed.
        if (this._added) {
            this._initCache()
        }

        return this
    }

    // legacy
    addPattern (pattern) {
        return this.add(pattern)
    }