docs: function __setMockFiles(newMockFiles) {
    mockFiles = Object.create(null);
    newMockFiles.forEach(function(file) {
      file = path.normalize(file);
      const dir = path.dirname(file);
      if (!mockFiles[dir]) {
        mockFiles[dir] = [];
      }
      mockFiles[dir].push(path.basename(file));
    });
  }