code: public ItemCollectionMetrics withItemCollectionKey(java.util.Map<String, AttributeValue> itemCollectionKey) {
          setItemCollectionKey(itemCollectionKey);
          return this;
      }
docs: <p>
  The partition key value of the item collection. This value is the same as the partition key value of the item.
  </p>
  
  @param itemCollectionKey
  The partition key value of the item collection. This value is the same as the partition key value of the
  item.
  @return Returns a reference to this object so that method calls can be chained together.