question: if this returns true , the graph is a directed graph . if false , it is undirected . concode_field_sep Map<String,Vertex<S,T>> labelToVertex concode_elem_sep boolean isDirected concode_field_sep List<String> topologicalSort concode_elem_sep void removeVertex concode_elem_sep List<String> shortestPath concode_elem_sep double getTotalCost concode_elem_sep HashMap<Vertex<S,T>,Vertex<S,T>> dijkstra concode_elem_sep List<Edge<S,T>> removeAllEdges concode_elem_sep Graph<S,T> minimumSpanningTree concode_elem_sep S getVertexData concode_elem_sep int getNumVertices concode_elem_sep Collection<String> getNeighbors concode_elem_sep T getEdgeData concode_elem_sep int getNumEdges concode_elem_sep Collection<String> getVertices concode_elem_sep boolean tarjanDFS concode_elem_sep Collection<Edge<S,T>> getEdges concode_elem_sep List<String> process_predecessors concode_elem_sep void addVertex concode_elem_sep void addEdge
target: boolean function ( ) { return isDirected ; }