@Override
        public boolean equals(final Object o) {
            if (this == o) {
                return true;
            }
            if (o == null || getClass() != o.getClass()) {
                return false;
            }
            final Key key = (Key) o;
            return Objects.equals(userRef, key.userRef) &&
                    Objects.equals(queryId, key.queryId);
        }
Registers a query as in progress and holds its taskid
stroom-meta/stroom-meta-impl/src/main/java/stroom/meta/impl/UserQueryRegistry.java