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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 edit_button_clicked(self, edit_button, exposure_combo_box, exposure):
 """Method to handle when an edit button is clicked. :param edit_button: The edit button. :type edit_button: QPushButton :param exposure_combo_box: The combo box of the exposure, contains list of classifications. :type exposure_combo_box: QComboBox :param exposure: Exposure definition. :type exposure: dict """

        # Note(IS): Do not change the text of edit button for now until we
        # have better behaviour.
        classification = self.get_classification(exposure_combo_box)

        if self.mode == CHOOSE_MODE:
            # Change mode
            self.mode = EDIT_MODE
            # Set active exposure
            self.active_exposure = exposure
            # Disable all edit button
            for exposure_edit_button in self.exposure_edit_buttons:
                exposure_edit_button.setEnabled(False)
            # Except one that was clicked
            # edit_button.setEnabled(True)
            # Disable all combo box
            for exposure_combo_box in self.exposure_combo_boxes:
                exposure_combo_box.setEnabled(False)
            # Change the edit button to cancel
            # edit_button.setText(tr('Cancel'))

            # Clear right panel
            clear_layout(self.right_layout)
            # Show edit threshold or value mapping
            if self.layer_mode == layer_mode_continuous:
                self.setup_thresholds_panel(classification)
            else:
                self.setup_value_mapping_panels(classification)
            self.add_buttons(classification)

        elif self.mode == EDIT_MODE:
            # Behave the same as cancel button clicked.
            self.cancel_button_clicked()

        self.parent.pbnNext.setEnabled(self.is_ready_to_next_step())