'Move back through the history list, fetching the previous command.'

def previous_history(self, current):

    if (self.history_cursor == len(self.history)):
        self.history.append(current.copy())
    if (self.history_cursor > 0):
        self.history_cursor -= 1
        current.set_line(self.history[self.history_cursor].get_line_text())
        current.point = lineobj.EndOfLine
