code: func (r *Result) IgnoreErrors(fns ...ErrMatchFunc) *Result {
  	for _, fn := range fns {
  		r.ignoreErrors = append(r.ignoreErrors, utilerrors.Matcher(fn))
  	}
  	return r
  }
docs: // IgnoreErrors will filter errors that occur when by visiting the result
  // (but not errors that occur by creating the result in the first place),
  // eliminating any that match fns. This is best used in combination with
  // Builder.ContinueOnError(), where the visitors accumulate errors and return
  // them after visiting as a slice of errors. If no errors remain after
  // filtering, the various visitor methods on Result will return nil for
  // err.