[Discuss-gnuradio] Attribute error

hey,

I have been working with Eigen value detection in GNU Radio..I am new to  this and i get the following error whenever i execute the flowgraph in  GRC.

 File "/home/abhishek/top_block.py", line 53, in __init__
    self.howto_detect_ff_0 = howto.detect_ff(100, 16, 1500)
AttributeError: 'module' object has no attribute 'detect_ff'

>>> Done

Any help will be appreciated,

Thanks in advance,

Abhishek