human
Solve the following python programming problem given the following code:
def prune(self, klass) : 
    def pr(left, right) : 
        ' create and return a new specialized BinOp from myself ' 
        if (left is None) : 
            return right 
else : 
            if (right is None) : 
                return left 
k = klass 
        if isinstance (left, ConditionBinOp) : 
            if (isinstance (left, ConditionBinOp) and isinstance (right, ConditionBinOp)) : 
                k = JointConditionBinOp 
else : 
                if isinstance (left, k) : 
                    return left 
else : 
                    if isinstance (right, k) : 
                        return right 
else : 
            if isinstance (left, FilterBinOp) : 
                if (isinstance (left, FilterBinOp) and isinstance (right, FilterBinOp)) : 
                    k = JointFilterBinOp 
else : 
                    if isinstance (left, k) : 
                        return left 
else : 
                        if isinstance (right, k) : 
                            return right 
return k (self.op, left, right, queryables = self.queryables, encoding = self.encoding).evaluate () 
(left, right) = (self.lhs, self.rhs) 
    if (is_term (left) and is_term (right)) : 
        res = pr (left.value, right.value) 
else : 
        if ((not is_term (left)) and is_term (right)) : 
            res = pr (left.prune (klass), right.value) 
else : 
            if (is_term (left) and (not is_term (right))) : 
                res = pr (left.value, right.prune (klass)) 
else : 
                if (not (is_term (left) or is_term (right))) : 
                    res = pr (left.prune (klass), right.prune (pr)) 
return res 

    
    

    Fix the buggy line: res = pr (left.prune (klass), right.prune (pr))
assistant
#Here is Python code to fix the buggy line: res = pr (left.

res = pr (left.prune (klass), right.prune (klass))