guava/src/com/google/common/collect/MultimapBuilder.java
public <K extends K0, V extends V0> Multimap<K, V> build(
      Multimap<? extends K, ? extends V> multimap) {
    Multimap<K, V> result = build();
    result.putAll(multimap);
    return result;
  }
public <K extends K0, V extends V0> Multimap<K, V> build(
      Multimap<? extends K, ? extends V> multimap) {
    Multimap<K, V> result = build();
    result.putAll(multimap);
    return result;
  }
public < K extends K0 , V extends V0 > Multimap < K , V > build ( Multimap < ? extends K , ? extends V > multimap ) { Multimap < K , V > result = build ( ) ; result . putAll ( multimap ) ; return result ; }
Returns a {@code Multimap} with the specified implementation, initialized with the entries of
{@code multimap}.
Returns a {