function collectCommentDirectives(node, directives, attrs, maxPriority, ignoreDirective) {
      // function created because of performance, try/catch disables
      // the optimization of the whole function #14848
      try {
        var match = COMMENT_DIRECTIVE_REGEXP.exec(node.nodeValue);
        if (match) {
          var nName = directiveNormalize(match[1]);
          if (addDirective(directives, nName, 'M', maxPriority, ignoreDirective)) {
            attrs[nName] = trim(match[2]);
          }
        }
      } catch (e) {
        // turns out that under some circumstances IE9 throws errors when one attempts to read
        // comment's node value.
        // Just ignore it and continue. (Can't seem to reproduce in test case.)
      }
    }
@ngdoc method
@name $locationProvider#hashPrefix
@description
The default value for the prefix is `'!'`.
@param {string=} prefix Prefix for hash part (containing path and search)
@returns {*} current value if used as getter or itself (chaining) if used as setter