toss({ baseUrl, skipIntercepted, retry: { count, backoff } }) {
    const { specs, pathPrefix } = this
    const testerBaseUrl = `${baseUrl}${pathPrefix}`

    const fn = this._only ? describe.only : describe
    // eslint-disable-next-line mocha/prefer-arrow-callback
    fn(this.title, function () {
      specs.forEach(spec => {
        spec._message = `[${spec.hasIntercept ? 'mocked' : 'live'}] ${
          spec._message
        }`
        if (!skipIntercepted || !spec.intercepted) {
          spec.baseUri(testerBaseUrl)
          spec.retry(count, backoff)
          spec.toss()
        }
      })
    })
  }
Register the tests with Mocha.

@param {object} attrs Refer to individual attrs
@param {string} attrs.baseUrl base URL for test server
@param {boolean} attrs.skipIntercepted skip tests which intercept requests
@param {object} attrs.retry retry configuration
@param {number} attrs.retry.count number of times to retry test
@param {number} attrs.retry.backoff number of milliseconds to add to the wait between each retry