public CopyResult call() throws Exception {
        copy.setState(TransferState.InProgress);
        if (isMultipartCopy()) {
            publishProgress(listenerChain, ProgressEventType.TRANSFER_STARTED_EVENT);
            copyInParts();
            return null;
        } else {
            return copyInOneChunk();
        }
    }
Returns true if this CopyCallable is processing a multi-part copy.

@return True if this CopyCallable is processing a multi-part copy.
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/transfer/internal/CopyCallable.java