@Override
        public void setup(final Memory memory) {
            assertFalse(memory.exists("m1"));  // or
            assertFalse(memory.exists("m2"));  // and
            assertFalse(memory.exists("m3"));  // long
            assertFalse(memory.exists("m4"));  // int
            memory.set("m1", false);
            memory.set("m2", true);
            memory.set("m3", 0l);
            memory.set("m4", 0);
        }
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