for i,s in enumerate(self.srcs[1:]):

            self.connect(s, (self.gui_snk, i+1))

        # Get Python Qt references

        pyQt  = self.gui_snk.pyqwidget()

        pyWin = sip.wrapinstance(pyQt, QtGui.QWidget)

            if(os.path.exists(f)):

                filesizes.append(os.path.getsize(f) / gr.sizeof_gr_complex)

        nsamples = max(filesizes)

    tb = my_top_block(filelist, options.sample_rate,

                      options.start, nsamples);