How to use the gprof2dot.Cycle function in gprof2dot

# to add them here
                    missing = Function(child.index, child.name)
                    function[TIME] = 0.0
                    function.called = 0
                    profile.add_function(missing)

                function.add_call(call)

            profile.add_function(function)

            if entry.cycle is not None:
                try:
                    cycle = cycles[entry.cycle]
                except KeyError:
                    sys.stderr.write('warning:  entry missing\n' % entry.cycle) 
                    cycle = Cycle()
                    cycles[entry.cycle] = cycle
                cycle.add_function(function)

            profile[TIME] = profile[TIME] + function[TIME]

        for cycle in compat_itervalues(cycles):
            profile.add_cycle(cycle)

        # Compute derived events
        profile.validate()
        profile.ratio(TIME_RATIO, TIME)
        profile.call_ratios(CALLS)
        profile.integrate(TOTAL_TIME, TIME)
        profile.ratio(TOTAL_TIME_RATIO, TOTAL_TIME)

        return profile

for call in compat_itervalues(function.calls):
            try:
                callee_data = data[call.callee_id]
                if callee_data.onstack:
                    func_data.lowlink = min(func_data.lowlink, callee_data.order)
            except KeyError:
                callee = self.functions[call.callee_id]
                order = self._tarjan(callee, order, stack, data)
                callee_data = data[call.callee_id]
                func_data.lowlink = min(func_data.lowlink, callee_data.lowlink)
        if func_data.lowlink == func_data.order:
            # Strongly connected component found
            members = stack[pos:]
            del stack[pos:]
            if len(members) > 1:
                cycle = Cycle()
                for member in members:
                    cycle.add_function(member)
                    data[member.id].onstack = False
            else:
                for member in members:
                    data[member.id].onstack = False
        return order

def parse(self):
        self.parse_cg()
        self.fp.close()

        profile = Profile()
        profile[TIME] = 0.0
        
        cycles = {}
        for index in self.cycles:
            cycles[index] = Cycle()

        for entry in compat_itervalues(self.functions):
            # populate the function
            function = Function(entry.index, entry.name)
            function[TIME] = entry.self
            if entry.called is not None:
                function.called = entry.called
            if entry.called_self is not None:
                call = Call(entry.index)
                call[CALLS] = entry.called_self
                function.called += entry.called_self
            
            # populate the function calls
            for child in entry.children:
                call = Call(child.index)