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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def on_btn_convert_3(self, event):
 """ Open dialog for rough conversion of 2.5 files to 3.0 files. Offer link to earthref for proper upgrade. """

        dia = pw.UpgradeDialog(None)
        dia.Center()
        res = dia.ShowModal()
        if res == wx.ID_CANCEL:
            webbrowser.open("https://www2.earthref.org/MagIC/upgrade", new=2)
            return
        ## more nicely styled way, but doesn't link to earthref
        #msg = "This tool is meant for relatively simple upgrades (for instance, a measurement file, a sample file, and a criteria file).\nIf you have a more complex contribution to upgrade, and you want maximum accuracy, use the upgrade tool at https://www2.earthref.org/MagIC/upgrade.\n\nDo you want to continue?"
        #result = pw.warning_with_override(msg)
        #if result == wx.ID_NO:
            #webbrowser.open("https://www2.earthref.org/MagIC/upgrade", new=2)
            #return
        # turn files from 2.5 --> 3.0 (rough translation)
        meas, upgraded, no_upgrade = pmag.convert_directory_2_to_3('magic_measurements.txt',
                                                                   input_dir=self.WD, output_dir=self.WD,
                                                                   data_model=self.contribution.data_model)
        if not meas:
            wx.MessageBox('2.5 --> 3.0 failed. Do you have a magic_measurements.txt file in your working directory?',
                          'Info', wx.OK | wx.ICON_INFORMATION)
            return

        # create a contribution
        self.contribution = cb.Contribution(self.WD)
        # make skeleton files with specimen, sample, site, location data
        self.contribution.propagate_measurement_info()
        # pop up
        upgraded_string = ", ".join(upgraded)
        if no_upgrade:
            no_upgrade_string = ", ".join(no_upgrade)
            msg = '2.5 --> 3.0 translation completed!\n\nThese 3.0 format files were created: {}.\n\nHowever, these 2.5 format files could not be upgraded: {}.\n\nTo convert all 2.5 files, use the MagIC upgrade tool: https://www2.earthref.org/MagIC/upgrade\n'.format(upgraded_string, no_upgrade_string)
            if 'criteria.txt' in upgraded:
                msg += '\nNote: Please check your criteria file for completeness and accuracy, as not all 2.5 files will be fully upgraded.'
            if 'pmag_criteria.txt' in no_upgrade:
                msg += '\nNote: Not all criteria files can be upgraded, even on the MagIC site.  You may need to recreate an old pmag_criteria file from scratch in Thellier GUI or Demag GUI.'
            wx.MessageBox(msg, 'Warning', wx.OK | wx.ICON_INFORMATION)
        else:
            msg = '2.5 --> 3.0 translation completed!\nThese files were converted: {}'.format(upgraded_string)
            wx.MessageBox(msg, 'Info', wx.OK | wx.ICON_INFORMATION)