Display the firsts lines (header) in the Curses interface.

        system + ip + uptime
        (cloud)

def __display_header(self, stat_display):
        """Display the firsts lines (header) in the Curses interface.

        system + ip + uptime
        (cloud)
        """
        # First line
        self.new_line()
        self.space_between_column = 0
        l_uptime = (self.get_stats_display_width(stat_display["system"]) +
                    self.get_stats_display_width(stat_display["ip"]) +
                    self.get_stats_display_width(stat_display["uptime"]) + 1)
        self.display_plugin(
            stat_display["system"],
            display_optional=(self.screen.getmaxyx()[1] >= l_uptime))
        self.space_between_column = 3
        self.new_column()
        self.display_plugin(stat_display["ip"])
        self.new_column()
        self.display_plugin(
            stat_display["uptime"],
            add_space=-(self.get_stats_display_width(stat_display["cloud"]) != 0))
        # Second line (optional)
        self.init_column()
        self.new_line()
        self.display_plugin(stat_display["cloud"])