How to create a Multimap from a Map?

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Assuming you have

Map<String, Collection<String>> map = ...;
Multimap<String, String> multimap = ArrayListMultimap.create();

Then I believe this is the best you can do

for (String key : map.keySet()) {
  multimap.putAll(key, map.get(key));
}

or the more optimal, but harder to read

for (Entry<String, Collection<String>> entry : map.entrySet()) {
  multimap.putAll(entry.getKey(), entry.getValue());
}

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