protected void filterMembers(Collection<ID> mbrs,
        Set<ID> matchingMembers, short requestType) {
      Set<ID> requests = getPendingRequestIDs(requestType);

      if (!requests.isEmpty()) {
        logger.debug(
            "filterMembers: processing " + requests.size() + " requests for type " + requestType);
        for (final ID memberID : requests) {
          if (mbrs.contains(memberID)) {
            testFlagForRemovalRequest = true;
            matchingMembers.add(memberID);
          }
        }
      }
    }
This gets pending requests and returns the IDs of any that are in the given collection

@param mbrs collection of IDs to search for
@param matchingMembers collection to store matching IDs in
@param requestType leave/remove/join
geode-membership/src/main/java/org/apache/geode/distributed/internal/membership/gms/membership/GMSJoinLeave.java