public Set<DistributedMember> findMembers(String[] groups, String[] members) {
    return ManagementUtils.findMembers(groups, members, cache);
  }
if no members matches these names, an empty set would return, this does not include locators

@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