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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def remove(self, qfield, value):
        ''' Atomically remove ``value`` from ``qfield``'''
        if isinstance(value, QueryExpression):
            return self._atomic_expression_op('$pull', qfield, value)
        return self._atomic_list_op('$pull', qfield, value)