        def _scroll(self, lines):
            """
            Scroll the window up or down.

            :param lines: Number of lines to scroll.  Negative numbers scroll
                down.
            """
            # Scroll the visible screen up by one line
            info = self._stdout.GetConsoleScreenBufferInfo()['Window']
            rectangle = win32console.PySMALL_RECTType(
                info.Left, info.Top + lines, info.Right, info.Bottom)
            new_pos = win32console.PyCOORDType(0, info.Top)
            self._stdout.ScrollConsoleScreenBuffer(
                rectangle, None, new_pos, " ", 0)
Scroll the window up or down.

:param lines: Number of lines to scroll.  Negative numbers scroll
down.
asciimatics/screen.py