def _swap(self,x):
        return (x[1],x[0])
Delete all occurrences of a specific header, if it is present.
dataset/ETHPy150Open scipy/scipy/scipy/sparse/csc.py/csc_matrix._swap--crossover with--dataset/ETHPy150Open ofermend/medicare-demo/socialite/jython/Lib/rfc822.py/Message.__delitem__