Click on the graph title to open any graph in edit mode. Edit mode quickly fills the entire page with
a clear view of the graph being edited. Grafana includes a built in target parser, it can help with
syntax errors but most importantly it can visualize the expression in other ways. For example unwrap the method calls and presents
the inner metric expression as a series of clickable segments followed by a chain of functions.
The parser and the unwrapping of functions has some current limitations (will be improved).
By clicking on the pen icon you can edit the expression in a text box instead.