@Override
            public DescribeUserScramCredentialsRequest.Builder createRequest(final int timeoutMs) {
                final DescribeUserScramCredentialsRequestData requestData = new DescribeUserScramCredentialsRequestData();

                if (users != null && !users.isEmpty()) {
                    final List<UserName> userNames = new ArrayList<>(users.size());

                    for (final String user : users) {
                        if (user != null) {
                            userNames.add(new UserName().setName(user));
                        }
                    }

                    requestData.setUsers(userNames);
                }

                return new DescribeUserScramCredentialsRequest.Builder(requestData);
            }
Returns the broker id pertaining to the given resource, or null if the resource is not associated
with a particular broker.
clients/src/main/java/org/apache/kafka/clients/admin/KafkaAdminClient.java