src/main/java/com/amazonaws/hal/HalService.java
private HalClient getHalClient() {
        if (halClient == null) {
            this.halClient = new HalClient(clientConfiguration == null ? new ClientConfiguration() : clientConfiguration,
                                           endpoint,
                                           serviceName,
                                           awsCredentialsProvider == null ? new DefaultAWSCredentialsProviderChain() : awsCredentialsProvider,
                                           resourceCache == null ? ImmediatelyExpiringCache.getInstance() : resourceCache,
                                           errorResponseHandler);

            if (regionId != null) {
                halClient.setSignerRegionOverride(regionId);
            }
        }

        return halClient;
    }
private HalClient getHalClient() {
        if (halClient == null) {
            this.halClient = new HalClient(clientConfiguration == null ? new ClientConfiguration() : clientConfiguration,
                                           endpoint,
                                           serviceName,
                                           awsCredentialsProvider == null ? new DefaultAWSCredentialsProviderChain() : awsCredentialsProvider,
                                           resourceCache == null ? ImmediatelyExpiringCache.getInstance() : resourceCache,
                                           errorResponseHandler);

            if (regionId != null) {
                halClient.setSignerRegionOverride(regionId);
            }
        }

        return halClient;
    }
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