text: import _Node, { attributeSetsMap, registerType } from './_Node.js'
  
  export default class Assertion extends _Node {
    static get name() {
      return 'Assertion'
    }
  
    constructor({ assertion, negated = false }, token) {
      super({ assertion, negated }, token)
    }
  
    get assertion() {
      return attributeSetsMap.get(this).assertion
    }
  
    get negated() {
      return attributeSetsMap.get(this).negated
    }
  
    toString() {
      const { assertion, negated } = this
      const negator = negated ? '!' : ''
  
      return `${negator}${assertion}`
    }
  }
  
  registerType(Assertion)
  