public Set<DistributedMember> findAnyMembersForRegion(String regionPath) {
    return ManagementUtils.getRegionAssociatedMembers(regionPath, cache, false);
  }
if no members matches these names, a UserErrorException will be thrown

@param groups names of groups to which returned members belong
@param members member names or IDs which returned members match
@return a set of matching members
geode-gfsh/src/main/java/org/apache/geode/management/cli/GfshCommand.java