code: function exists(file, src, opts) {
  	var files = opts.path.map(function (dir) {
  		return path.join(dir, file);
  	});
  
  	files = globby.sync(files);
  
  	if (!files.length) {
  		throw new Error(createError(file, src, opts.path));
  	}
  
  	return files[0];
  }
docs: Check if a file exists
  
  @param {String} file
  @param {String} src
  @param {Object} opts
  @api private