Draw the given breakpoint pixmap.

        Args:
            top (int): top of the line to draw the breakpoint icon.
            painter (QPainter)
            icon_name (srt): key of icon to draw (see: self.icons)

def _draw_breakpoint_icon(self, top, painter, icon_name):
        """Draw the given breakpoint pixmap.

        Args:
            top (int): top of the line to draw the breakpoint icon.
            painter (QPainter)
            icon_name (srt): key of icon to draw (see: self.icons)
        """
        rect = QRect(0, top, self.sizeHint().width(),
                     self.sizeHint().height())
        try:
            icon = self.icons[icon_name]
        except KeyError as e:
            debug_print("Breakpoint icon doen't exist, {}".format(e))
        else:
            icon.paint(painter, rect)