@Nullable
	public InheritanceVertex getVertex(@Nonnull String name) {
		InheritanceVertex vertex = vertices.get(name);
		if (vertex == null && !stubs.contains(name)) {
			// Vertex does not exist and was not marked as a stub.
			// We want to look up the vertex for the given class and figure out if its valid or needs to be stubbed.
			InheritanceVertex provided = createVertex(name);
			if (provided == STUB || provided == null) {
				// Provider yielded either a stub OR no result. Discard it.
				stubs.add(name);
			} else {
				// Provider yielded a valid vertex. Update the return value and record it in the map.
				vertices.put(name, provided);
				vertex = provided;
			}
		}
		return vertex;
	}
@param name
		Class name.

@return Vertex in graph of class. {@code null} if no such class was found in the inputs.
recaf-core/src/main/java/software/coley/recaf/services/inheritance/InheritanceGraph.java