public DynamoDBTransactionWriteExpression withExpressionAttributeNames(Map<String, String> expressionAttributeNames) {
        this.expressionAttributeNames = expressionAttributeNames;
        return this;
    }
One or more substitution tokens for attribute names in an expression.
aws-java-sdk-dynamodb/src/main/java/com/amazonaws/services/dynamodbv2/datamodeling/DynamoDBTransactionWriteExpression.java