SummarySetOperations (datasketches-java 4.2.0 API)

Type Parameters:

S - type of Summary

All Known Implementing Classes:

ArrayOfStringsSummarySetOperations, DoubleSummarySetOperations, IntegerSummarySetOperations
```
public interface SummarySetOperations<S extends Summary>
```
This is to provide methods of producing unions and intersections of two Summary objects.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`S`	`intersection(S a, S b)`	This is called by the intersection operator when both sketches have the same hash value.
`S`	`union(S a, S b)`	This is called by the union operator when both sketches have the same hash value.

- Method Detail
  - union
```
S union(S a,
        S b)
```
    This is called by the union operator when both sketches have the same hash value.
    Caution: Do not modify the input Summary objects. Also do not return them directly, unless they are immutable (most Summary objects are not). For mutable Summary objects, it is important to create a new Summary object with the correct contents to be returned. Do not return null summaries.
    
    Parameters:
    
    a - Summary from sketch A
    
    b - Summary from sketch B
    
    Returns:
    
    union of Summary A and Summary B
  - intersection
```
S intersection(S a,
               S b)
```
    This is called by the intersection operator when both sketches have the same hash value.
    Caution: Do not modify the input Summary objects. Also do not return them directly, unless they are immutable (most Summary objects are not). For mutable Summary objects, it is important to create a new Summary object with the correct contents to be returned. Do not return null summaries.
    
    Parameters:
    
    a - Summary from sketch A
    
    b - Summary from sketch B
    
    Returns:
    
    intersection of Summary A and Summary B