public final void setMultipartCopyThreshold(Long multipartCopyThreshold) {
        this.multipartCopyThreshold = multipartCopyThreshold;
    }
Sets the size threshold, in bytes, for when to use multi-part copy. Copy requests for objects
over this size will automatically use a multi-part copy strategy, while copy requests for
objects smaller than this threshold will use a single connection to copy the whole object.

@param multipartCopyThreshold Threshold in which multipart copies will be performed.
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/transfer/TransferManagerBuilder.java