code: function buildPaths(file, arr) {
      if (!grunt.file.exists(file)) {
        grunt.log.warn('File "' + file + '" not found');
        return null;
      }
      arr.unshift(file);
      var namespaces = pathTable[file];
      if (namespaces && namespaces.length) {
        for (var i = namespaces.length, ns; i-- > 0;) {
          ns = namespaces[i];
          if (!nsTable[ns]) {
            throw new Error(
              'Required namespace "' + ns + '" not found in ' + file);
          }
          buildPaths(nsTable[ns], arr);
        }
      }
      return arr;
    }
docs: Recursively builds file paths array from specified file and assigns them to
  array parameter. Uses pathTable to look up namespace dependencies.
  @param {string} file File path.
  @param {Array} arr Array to store file paths.
  @returns {Array|null} Array of file paths.