@Override
            public AlterUserScramCredentialsRequest.Builder createRequest(int timeoutMs) {
                return new AlterUserScramCredentialsRequest.Builder(
                        new AlterUserScramCredentialsRequestData().setUpsertions(alterations.stream()
                                .filter(a -> a instanceof UserScramCredentialUpsertion)
                                .filter(a -> !userIllegalAlterationExceptions.containsKey(a.user()))
                                .map(a -> userInsertions.get(a.user()).get(((UserScramCredentialUpsertion) a).credentialInfo().mechanism()))
                                .collect(Collectors.toList()))
                        .setDeletions(alterations.stream()
                                .filter(a -> a instanceof UserScramCredentialDeletion)
                                .filter(a -> !userIllegalAlterationExceptions.containsKey(a.user()))
                                .map(d -> getScramCredentialDeletion((UserScramCredentialDeletion) d))
                                .collect(Collectors.toList())));
            }
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