code: public TransactionWriteRequest addPut(Object object, DynamoDBTransactionWriteExpression transactionWriteExpression) {
          return addPut(object, transactionWriteExpression, null /* returnValuesOnConditionCheckFailure */);
      }
docs: Adds put operation (to be executed on object) to the list of transaction write operations.
  transactionWriteExpression is used to conditionally put object.