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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 source(self):
 """Parameters for saving zip backups"""

        with gui.FlexForm(self.title, auto_size_text=True, default_element_size=(40, 1)) as form:
            layout = [
                [gui.Text('Zip Backup utility', size=(30, 1), font=("Helvetica", 30), text_color='blue')],
                [gui.Text('Create a zip backup of a file or directory.', size=(50, 1), font=("Helvetica", 18),
                          text_color='black')],
                [gui.Text('-' * 200)],

                # Source
                [gui.Text('Select source folder', size=(20, 1), font=("Helvetica", 25), auto_size_text=False),
                 gui.InputText('', key='source', font=("Helvetica", 20)),
                 gui.FolderBrowse()],

                [gui.Submit(), gui.Cancel()]]

            button, values = form.LayoutAndRead(layout)
            if button == 'Submit':
                return values['source']
            else:
                exit()