Is there a simple function for joining all elements and key values, to a String

```
Map<String, String> m = new HashMap<String, String>();
m.put("lebron", "james");
m.put("kevin", "durant");

```

m.join(",") should produce: "lebronjames,kevindurant"

I'm looking for a simpler (less verbose) solution using guava or apache common (StringUtils) Java libs, instead of iterating over the map