private Set getAllClientsWithInterest() {
    Set clientsWithInterest = new HashSet(getAllKeyClients());
    clientsWithInterest.addAll(getPatternsOfInterest().keySet());
    clientsWithInterest.addAll(getFiltersOfInterest().keySet());
    clientsWithInterest.addAll(getKeysOfInterest().keySet());
    return clientsWithInterest;
  }
return a set containing all clients that have registered interest for values
geode-core/src/main/java/org/apache/geode/internal/cache/FilterProfile.java