# Class: com.pnfsoftware.jeb.util.base.Couple

Handy class holding two typed elements. Null values are allowed.

## Constructor: Couple
- parameter: `a`, type: `A`
- parameter: `b`, type: `B`

Description: Create a pair.
parameter: a: first element
parameter: b: second element

## Method: equals
- parameter: `obj`, type: `java.lang.Object`
- return type: `boolean`


## Method: getFirst
- return type: `A`

Description: 
return: the first element

## Method: getSecond
- return type: `B`

Description: 
return: the second element

## Method: hashCode
- return type: `int`


## Method: setFirst
- parameter: `a`, type: `A`

Description: 
parameter: a: first element

## Method: setSecond
- parameter: `b`, type: `B`

Description: 
parameter: b: second element

## Method: toString
- return type: `java.lang.String`


## Static Method: getFirstElements
- parameter: `couples`, type: `java.util.Collection<com.pnfsoftware.jeb.util.base.Couple<A,B>>`
- return type: `java.util.Collection<A>`

Description: Extract the first element of each pair.
parameter: A: type of first elements
parameter: B: type of second elements
parameter: couples: input pairs
return: first elements, in iteration order

## Static Method: getSecondElements
- parameter: `couples`, type: `java.util.Collection<com.pnfsoftware.jeb.util.base.Couple<A,B>>`
- return type: `java.util.Collection<B>`

Description: Extract the second element of each pair.
parameter: A: type of first elements
parameter: B: type of second elements
parameter: couples: input pairs
return: second elements, in iteration order