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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 block_transfer(self, buffer, x, y):
 """ Copy a buffer entirely to this double buffer. :param buffer: The double buffer to copy :param x: The X origin for where to place it in this buffer :param y: The Y origin for where to place it in this buffer """

        # Just copy the double-buffer cells - the real screen will sync on refresh.
        block_min_x = max(0, x)
        block_max_x = min(x + buffer.width, self._width)

        # Check for trivial non-overlap
        if block_min_x > block_max_x:
            return

        # Copy the available section
        for by in range(0, self._height):
            if y <= by < y + buffer.height:
                self._double_buffer[by][block_min_x:block_max_x] = buffer.slice(
                    block_min_x - x, by - y, block_max_x - block_min_x)