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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 fill_area(self, x, y, width, height, color, opacity = 1):
 """fill rectangular area with specified color"""

        self.save_context()
        self.rectangle(x, y, width, height)
        self._add_instruction("clip")
        self.rectangle(x, y, width, height)
        self.fill(color, opacity)
        self.restore_context()