SetMultimapBuilder<K, V>  constructor 
      
      SetMultimapBuilder<K, V> ([ 
    
- dynamic multimap = const {}
Instantiates with elements from a Map, SetMultimap or
BuiltSetMultimap.
Implementation
factory SetMultimapBuilder([multimap = const {}]) {
  return SetMultimapBuilder<K, V>._uninitialized()..replace(multimap);
}