removeRule (rule) {
    let ruleRemoved = false
    if (!(rule instanceof Rule)) {
      const filteredRules = this.rules.filter(ruleInEngine => ruleInEngine.name !== rule)
      ruleRemoved = filteredRules.length !== this.rules.length
      this.rules = filteredRules
    } else {
      const index = this.rules.indexOf(rule)
      if (index > -1) {
        ruleRemoved = Boolean(this.rules.splice(index, 1).length)
      }
    }
    if (ruleRemoved) {
      this.prioritizedRules = null
    }
    return ruleRemoved
  }
Remove a rule from the engine
@param {object|Rule|string} rule - rule definition. Must be a instance of Rule