merge<R, V> abstract method 
    
      
Maybe<R>
merge<
R, V>( - Maybe<V> other, 
- Merger<R, T, V> merger
) 
    
  If this and the other are both Just values, merges them using the merger function and returns Just
 
    
  Implementation
  Maybe<R> merge<R, V>(Maybe<V> other, Merger<R, T, V> merger);