title: How do I add labels to CPBarPlot barplots?
body: <p>I'm completely new to Core Plot and have a working bar graph, but the visual is kind of useless for me unless I know which object is represented in each bar.  I have seen that there is a method called 'fieldIdentifiers' but do not know how to implement it, nor can I find any documentation (if this even the correct method).  Can you steer me in the right direction?  Thanks!</p>