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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 _syscall(self, command, input=None, env=None, *params):
        '''
        Call an external system command.
        '''
        return Popen([command] + list(params), stdout=PIPE, stdin=PIPE, stderr=STDOUT,
                     env=env or os.environ).communicate(input=input)