AttributeError: type object 'dect2' has no attribute 'phase_diff'

[c5e3]

Traceback (most recent call last):
  File "/home/c5e3/git/gr-dect2/grc/dect2.py", line 260, in <module>
    main()
  File "/home/c5e3/git/gr-dect2/grc/dect2.py", line 248, in main
    tb = top_block_cls()
  File "/home/c5e3/git/gr-dect2/grc/dect2.py", line 134, in __init__
    self.dect2_phase_diff_0 = dect2.phase_diff()
AttributeError: type object 'dect2' has no attribute 'phase_diff'

dect2.zip