code: function getWebpackStats(config) {
  
      let statsPaths = config.testPathDirs.map(testPathDir => {
          return path.join(testPathDir, 'stats.json');
      });
  
      statsPaths.some(statsPath => {
          try {
              webpackStats = require(statsPath);
          } catch (oh) {
              // not found
          }
          return !!webpackStats;
      });
  
      if (!webpackStats) {
          throw new Error('Cannot find Webpack stats in: \n' + statsPaths.join('\n'));
      }
  
      return webpackStats;
  }
docs: Checks the root of each `config.testPathDirs` directory for the Webpack `stats.json`.
  @param  {Object} config The Jest config.
  @return {Object}        The Webpack stats json.