update node with a map.
Source
RemoteNode updateRemoteChildNode(RemoteNode parent, String name, Map m) { String path; if (parent.remotePath == '/') { path = '/$name'; } else { path = '${parent.remotePath}/$name'; } RemoteNode rslt; if (_nodes.containsKey(path)) { rslt = _nodes[path]; rslt.updateRemoteChildData(m, this); } else { rslt = new RemoteNode(path); _nodes[path] = rslt; rslt.updateRemoteChildData(m, this); } return rslt; }