@Override
    public DeleteItemSpec withRequestMetricCollector(
            RequestMetricCollector requestMetricCollector) {
        setRequestMetricCollector(requestMetricCollector);
        return this;
    }
Applicable only when an expression has been specified. Used to
specify the actual values for the attribute-value placeholders.
aws-java-sdk-dynamodb/src/main/java/com/amazonaws/services/dynamodbv2/document/spec/DeleteItemSpec.java