Get the neighborhood of a node in a graph

That is, find all nodes connected to node by an outgoing edge. This function is memorized to avoid making repeated API queries.

neighborhood(graph, node)

Arguments

graph	A graph object.
nodes	The name of a single node in graph as a character vector.

Value

A character vector of all nodes in graph connected such that there is an outgoing edge for node to those nodes. This should never be empty, as neighborhood() should not be called on nodes that fail check().