[Discuss-gnuradio] using control_loop in OOT module , AttributeError: 'module' object has no attribute

Hi ,
I want to use control_loop block in my custom cpp out of tree module ,
for start i'm trying to make some thing like pll_carriertracking_cc
when i add just control_loop to virtual public class in header file in
include folder .

I can compile and install module without problem but wen i try to
execute flow graph i got this error :

self.ashtum_fll_cc_1 = ashtum.fll_cc(6.28/100, .4, -.4)
AttributeError: 'module' object has no attribute 'fll_cc'

‌But when i remove "virtual public blocks::control_loop" line every
thing become ok and of course i can't use control_loop members but
myblock (fll_cc) run in flow graph without any problem .

This my header file fll_cc.h :

#ifndef INCLUDED_ASHTUM_FLL_CC_H
#define INCLUDED_ASHTUM_FLL_CC_H

#include <ashtum/api.h>
#include <gnuradio/sync_block.h>
#include <gnuradio/blocks/control_loop.h>

namespace gr {
namespace ashtum {

class ASHTUM_API fll_cc
: virtual public sync_block,
virtual public blocks::control_loop
{
public:
typedef boost::shared_ptr<fll_cc> sptr;
static sptr make(float loop_bw, float max_freq, float min_freq);
virtual bool lock_detector(void) = 0;
virtual bool squelch_enable(bool) = 0;
virtual float set_lock_threshold(float) = 0;

};

} // namespace ashtum
} // namespace gr