Now know is that by setting a known value, and then through the map entry. The getValue (), and whether the given value is equal, if equal, then insert the key in the list, add the circulation,
And I think in the case of not clear the key and the value through the value: the key of the case, and may have the same value, the final result of different key, it should be
{value1: key1} {value1: key100} {value2: key} and {value1: key1, value1: key100, value2: key}