human
Solve the following python programming problem given the following code:
@ Substitution (name = 'ewm') 
@ Appender (_doc_template) 
@ Appender (_pairwise_template) 
def cov(self, other = None, pairwise = None, bias = False, **kwargs) : 
    'exponential weighted sample covariance' 
    if (other is None) : 
        other = self._selected_obj 
        pairwise = (True if (pairwise is None) else pairwise) 
other = self._shallow_copy (other) 
    def _get_cov(X, Y) : 
        X = self._shallow_copy (X) 
        Y = self._shallow_copy (Y) 
        cov = algos.ewmcov (X._prep_values (), Y._prep_values (), self.com, int (self.adjust), int (self.ignore_na), int (self.min_periods), int (bias)) 
        return X._wrap_result (cov) 
return _flex_binary_moment (self._selected_obj, other._selected_obj, _get_cov, pairwise = bool (other)) 

    
    

    Fix the buggy line: return _flex_binary_moment (self._selected_obj, other._selected_obj, _get_cov, pairwise = bool (other))
assistant
#Here is Python code to fix the buggy line: return _flex_binary_moment (self.

return _flex_binary_moment (self._selected_obj, other._selected_obj, _get_cov, pairwise = bool (pairwise))