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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 expand_all(self):
 """Expands all fold triggers."""

        block = self.editor.document().firstBlock()
        while block.isValid():
            TextBlockHelper.set_collapsed(block, False)
            block.setVisible(True)
            block = block.next()
        self._clear_block_deco()
        self._refresh_editor_and_scrollbars()
        self.expand_all_triggered.emit()