human
Solve the following python programming problem given the following code:
@ derived_from (pd.DataFrame) 
def dropna(self, how = 'any', subset = None) : 
    def f(df, how = how, subset = subset) : 
        return df.dropna (how = how, subset = subset) 
return self.map_partitions (f, how = self, subset = subset) 

    
    

    Fix the buggy line: return self.map_partitions (f, how = self, subset = subset)
assistant
#Here is Python program to fix the buggy line: return self.

return self.map_partitions (f, how = how, subset = subset)