docs: function saveCoverage(opts) {
    const coveragePath = path.join(opts.coverage, 'coverage.json');
    const coverage = systemIstanbul.remapCoverage();
  
    sh.echo(`Saving coverage data in ${coveragePath}...`);
  
    fs.writeFileSync(coveragePath, JSON.stringify(coverage));
  
    return coverage;
  }