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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 find_faces(self, image, draw_box=False):
 """Uses a haarcascade to detect faces inside an image. Args: image: The image. draw_box: If True, the image will be marked with a rectangle. Return: The faces as returned by OpenCV's detectMultiScale method for cascades. """

        frame_gray = cv2.cvtColor(image, cv2.COLOR_RGB2GRAY)
        faces = self.cascade.detectMultiScale(
            frame_gray,
            scaleFactor=1.3,
            minNeighbors=5,
            minSize=(50, 50),
            flags=0)

        if draw_box:
            for x, y, w, h in faces:
                cv2.rectangle(image, (x, y),
                              (x + w, y + h), (0, 255, 0), 2)
        return faces