    graph.getNeighbors(element [, opt])

Get all the neighbors of `element` in the graph. Neighbors are all the elements connected to `element` via either an inbound or an outbound link. If `opt.inbound` is `true`, only inbound neighbords (all neighbors connected with a link who's `target` is the `element`) will be returned. Similarly, if `opt.outbound` is `true`, only outbound neighbors will be returned. If `opt.deep` is `true`, return also all the neighbors of all the elements embedded inside `element`.