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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 contour_mask(self, contour):
 """ Generates a binary image with only the given contour filled in. """

        # fill in new data
        new_data = np.zeros(self.data.shape)
        num_boundary = contour.boundary_pixels.shape[0]
        boundary_px_ij_swapped = np.zeros([num_boundary, 1, 2])
        boundary_px_ij_swapped[:, 0, 0] = contour.boundary_pixels[:, 1]
        boundary_px_ij_swapped[:, 0, 1] = contour.boundary_pixels[:, 0]
        cv2.fillPoly(
            new_data, pts=[
                boundary_px_ij_swapped.astype(
                    np.int32)], color=(
                BINARY_IM_MAX_VAL, BINARY_IM_MAX_VAL, BINARY_IM_MAX_VAL))
        orig_zeros = np.where(self.data == 0)
        new_data[orig_zeros[0], orig_zeros[1]] = 0
        return BinaryImage(new_data.astype(np.uint8), frame=self._frame)