I have a question regarding Treemaps. I understand how to use the keys to get the values associated with them.

for example,

If I have names "Bob" and "Joe" mapped to "1" and "2" respectively, I can get the values 1 and 2 by using the get() method with "Bob" or "Joe" as the parameters.

My question is this. How can I do it in reverse? As in, I want to be able to find out what keys are mapped to certain values. Like if I want to see what name is mapped to "2", how can I go about doing this? I haven't been able to locate an easy way to do this so far, but there has to be a way?