function selfLinking(link, id) {
  return getNodeID(link.source, id) == getNodeID(link.target, id);
}
function selfLinking(link, id) {
  return getNodeID(link.source, id) == getNodeID(link.target, id);
}
function selfLinking ( link , id ) { return getNodeID ( link . source , id ) == getNodeID ( link . target , id ) ; }
check if link is self linking, ie links a node to the same node
check if link is self linking ie links a node to the same node