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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_comment_entered(self):
 """The user has typed a comment"""

        text_edit = self.findChild(QtWidgets.QWidget, "CommentBox")
        comment = text_edit.text()

        # Store within context
        context = self.controller.context
        context.data["comment"] = comment

        placeholder = self.findChild(QtWidgets.QLabel, "CommentPlaceholder")
        placeholder.setVisible(not comment)