code: function findSignature(node) {
    if (!node.leadingComments) {
      return;
    }
  
    var m;
    for (var i = 0; i < node.leadingComments.length; i++) {
      m = node.leadingComments[i].value.match(/::\s*(.*)/);
      if (m) {
        break;
      }
    }
    if (!m) {
      return;
    }
  
    return m[1];
  }
docs: Find comments with ::