docs: function chaiMatchrPlugin(chai, chaiUtils) {
  
    const Assertion = chai.Assertion;
    const flag = chaiUtils.flag;
    const assert = chai.assert;
  
    Assertion.addMethod('matchr', function chaiMatchr(pattern, options) {
      const value = flag(this, 'object');
      const negate = Boolean(flag(this, 'negate'));
      assert(
        matchr(value, pattern, options) !== negate,
        `Expected ${pretty(value)} to ${negate ? 'not ' : ''}match ${pretty(pattern)}`
      );
    });
  }