public void deleteIfExists(T object) throws ConditionalCheckFailedException {
        final DynamoDBDeleteExpression deleteExpression = new DynamoDBDeleteExpression();
        for (final DynamoDBMapperFieldModel<T,Object> key : model.keys()) {
            deleteExpression.withExpectedEntry(key.name(), new ExpectedAttributeValue()
                .withExists(true).withValue(key.convert(key.get(object))));
        }
        mapper.delete(object, deleteExpression);
    }
Deletes the given object from its DynamoDB table with the condition that
the hash and, if applicable, the range key, already exist.
@param object The object to delete.
@throws ConditionalCheckFailedException If the object does not exist.
@see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper#delete
@see com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBDeleteExpression
@see com.amazonaws.services.dynamodbv2.model.ExpectedAttributeValue
aws-java-sdk-dynamodb/src/main/java/com/amazonaws/services/dynamodbv2/datamodeling/DynamoDBTableMapper.java