@classmethod
def insstr(cls, s, x=None, y=None, attr=None):
    """
        Insert a string at cursor or specified position.
        Cursor is not moved and characters to the right are shifted right.

        :param s: the string
        :param x: optional x value
        :param y: optional y value
        :param attr: optional attributes
        """
    x, y = cls._fix_xy(x, y)
    attr = cls._fix_attr(attr)
    if attr is None:
        return cls.WINDOW.insstr(y, x, s)
    else:
        return cls.WINDOW.insstr(y, x, s, attr)
