public final Subclass withEndpointConfiguration(EndpointConfiguration endpointConfiguration) {
        this.endpointConfiguration = endpointConfiguration;
        return getSubclass();
    }
Sets the endpoint configuration (service endpoint & signing region) to be used for requests. If neither region {@link #withRegion(String)}
or endpoint configuration are explicitly provided in the builder the {@link #DEFAULT_REGION_PROVIDER} is consulted.

<p><b>Only use this if using a non-standard service endpoint - the recommended approach for configuring a client is to use {@link #withRegion(String)}</b>

@param endpointConfiguration The endpointConfiguration to use
@return This object for method chaining.
aws-java-sdk-core/src/main/java/com/amazonaws/client/builder/AwsClientBuilder.java