docs: def do_help(self, line):
          """Displays help information."""
          print ""
          print "Perfdump CLI provides a handful of simple ways to query your"
          print "performance data."
          print ""
          print "The simplest queries are of the form:"
          print ""
          print "\t[slowest|fastest] [tests|setups]"
          print ""
          print "For example:"
          print ""
          print "\tperfdump > slowest tests"
          print ""
          print "Prints the slowest 10 tests"
          print ""
          print "Additional grouping of results can be request."
          print ""
          print "\tperfdump > slowest tests groupby file"
          print ""
          print "Grouping options include:"
          print ""
          print "\tfile | module | class | function"
          print ""