MultiMap (uk.gov.gchq.gaffer:gaffer2 2.2.0 API)

Type Parameters:

K - the type of key

V - the type of value

All Known Implementing Classes:

MapOfSets
```
public interface MultiMap<K,V>
```
Map-like data structure where keys may correspond to multiple values.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`void`	`clear()`	Clear the map of all entries.
`Collection<V>`	`get(K key)`	Get all of the values associated with the specified key.
`Set<K>`	`keySet()`	Get the Set containing all keys in the map.
`void`	`put(K key, Collection<V> values)`	Add a collection of values to the specified key.
`boolean`	`put(K key, V value)`	Add a value to the specified key.
`default void`	`putAll(MultiMap<K,V> map)`	Add all of the contents of another `MultiMap` to this instance.

- Method Detail
  - put
```
boolean put(K key,
            V value)
```
    Add a value to the specified key.
    
    Parameters:
    
    key - the key to add a value to
    
    value - the value to add
    
    Returns:
    
    true if the operation was successful, otherwise false
  - put
```
void put(K key,
         Collection<V> values)
```
    Add a collection of values to the specified key.
    
    Parameters:
    
    key - the key to add the values to
    
    values - the values to add
  - get
```
Collection<V> get(K key)
```
    Get all of the values associated with the specified key.
    
    Parameters:
    
    key - the key to lookup
    
    Returns:
    
    a collection containing all of the values
  - keySet
```
Set<K> keySet()
```
    Get the Set containing all keys in the map.
    
    Returns:
    
    the set of keys
  - clear
```
void clear()
```
    Clear the map of all entries.
  - putAll
```
default void putAll(MultiMap<K,V> map)
```
    Add all of the contents of another MultiMap to this instance.
    
    Parameters:
    
    map - the map containing the entries to add to this map instance