human
Solve the following python programming problem given the following code:
def memoize(rule) : 
    ' Memoized version of a rule ' 
    cache = { 
        
} 
    def memoized_rl(expr) : 
        if (expr in cache) : 
            return cache [expr] 
else : 
            result = rule (expr) 
            cache [expr] = result 
            return result 
return cache 

    
    

    Fix the buggy line: return cache
assistant
#Here is Python code to fix the buggy line: return cache
.

return def memoized_rl(