public UpdateUsageResult addItemsEntry(String key, java.util.List<java.util.List<Long>> value) {
        if (null == this.items) {
            this.items = new java.util.HashMap<String, java.util.List<java.util.List<Long>>>();
        }
        if (this.items.containsKey(key))
            throw new IllegalArgumentException("Duplicated keys (" + key.toString() + ") are provided.");
        this.items.put(key, value);
        return this;
    }
Add a single Items entry

@see UpdateUsageResult#withItems
@returns a reference to this object so that method calls can be chained together.
aws-java-sdk-api-gateway/src/main/java/com/amazonaws/services/apigateway/model/UpdateUsageResult.java