@Override
  public ImmutableSetMultimap<V, K> inverse() {
    ImmutableSetMultimap<V, K> result = inverse;
    return (result == null) ? (inverse = invert()) : result;
  }
@Override
  public ImmutableSetMultimap<V, K> inverse() {
    ImmutableSetMultimap<V, K> result = inverse;
    return (result == null) ? (inverse = invert()) : result;
  }
@ Override public ImmutableSetMultimap < V , K > inverse ( ) { ImmutableSetMultimap < V , K > result = inverse ; return ( result == null ) ? ( inverse = invert ( ) ) : result ; }
{@inheritDoc}

<p>Because an inverse of a set multimap cannot contain multiple pairs with the same key and
value, this method returns an {@code ImmutableSetMultimap} rather than the {@code
ImmutableMultimap} specified in the {@code ImmutableMultimap} class.
{ @inheritDoc }