async function assertReporterOutputEquality(reporter) {
  const {actual, expected} = await compareReporters(reporter);
  return expect(actual, 'to satisfy', {
    passing: expected.passing,
    failing: expected.failing,
    pending: expected.pending,
    code: expected.code,
    output: expected.output
  });
}
Many (but not all) reporters can use this assertion to compare output of serial vs. parallel
@param {string} reporter - Reporter name