Context (ZK Pivot Table Components 3.1.0 API)

All Known Implementing Classes:

MinMaxContext, ProductContext, SumCountContext, VarianceContext
```
public interface Context<C extends Context<C>>
```
The context to hold intermediate result of an aggregation. For example, to calculate arithmetic average, we need to accumulate SUM and COUNT. It is provable that if an aggregation over a collection is order independent and its computation can be carried out via a context data type with a binary operator, then the context can also be merged from contexts over a partition of the original collection.

Author:

simonpai

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`add(Object item)`	Add an item into the aggregation.
`void`	`merge(C ctx)`	Merge from another context of the same type.

- Method Detail
  - add
```
void add(Object item)
```
    Add an item into the aggregation.
  - merge
```
void merge(C ctx)
```
    Merge from another context of the same type.