returns the labels of all vertices within the graph . concode_field_sep List<VertexLabelType> vertexLabels concode_elem_sep Hashtable<VertexLabelType,Hashtable<VertexLabelType,EdgeLabelType>> globalEdgeLookup concode_field_sep void set concode_elem_sep List<VertexLabelType> getSuccessors concode_elem_sep EdgeLabelType get concode_elem_sep boolean isVertexLabel concode_elem_sep void clear concode_elem_sep Hashtable<VertexLabelType,EdgeLabelType> checkForNewVertex concode_elem_sep void addVertex concode_elem_sep void remove