<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def set_link(self, link,y=0,page=-1):
        "Set destination of internal link"
        if(y==-1):
            y=self.y
        if(page==-1):
            page=self.page
        self.links[link]=[page,y]