@SuppressWarnings("unchecked")
            @Override
            public VertexProgramQ create(final Graph graph) {
                if (graph != null) {
                    ConfigurationUtils.append(graph.configuration().subset(VERTEX_PROGRAM_Q_CFG_PREFIX), configuration);
                }
                return (VertexProgramQ) VertexProgram.createVertexProgram(graph, configuration);
            }
Javadoc for {@code ConcurrentSkipListSet} includes this little note: "Beware that, unlike in most
collections, the size method is not a constant-time operation." Doing a traversal of elements will yield
the correct count. Java 11 upgrade seemed to force this failure consistently.
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/computer/GraphComputerTest.java