human
Solve the following python programming problem given the following code:
def _set_rate(self, rate) : 
    def set_hash_payment_rate(rate) : 
        self.payment_rate_manager.min_valuable_blob_hash_payment_rate = rate 
d = self.settings.save_valuable_hash_payment_rate (set_hash_payment_rate) 
    d.addCallback ((lambda _ : set_hash_payment_rate (rate))) 
    return d 

    
    

    Fix the buggy line: d = self.settings.save_valuable_hash_payment_rate (set_hash_payment_rate)
assistant
#Here is Python program to fix the buggy line: d = self.

d = self.settings.save_valuable_hash_payment_rate (rate)