public final Subclass withCredentials(AWSCredentialsProvider credentialsProvider) {
        setCredentials(credentialsProvider);
        return getSubclass();
    }
Sets the AWSCredentialsProvider used by the client. If not specified the default is {@link
DefaultAWSCredentialsProviderChain}.

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