If used, this function should be called before Curses.initscr or newterm are called.
When flag is false, the values of lines and columns specified in the terminfo database will be used, even if environment variables Curses.LINES and Curses.COLS (used by default) are set, or if curses is running in a window (in which case default behavior would be to use the window size if Curses.LINES and Curses.COLS are not set).