code: def seek_data(self, element, npos):
      print("seek %d" % npos)
      self.pos = npos // self.per_sample
      return True
  
imports: from __future__ import division
  import gi
  from gi.repository import GLib, Gst
  import numpy
  import scipy.signal.waveforms
  import os.path
  import ffmpeg
label_desc: Use image node_id 3 for calling the NumpySrc obj's underlying member method code with example usage: obj.seek_data(element, npos) and returns: True