def read_line(self, *args):
        """\
        Helper function to read a single line from a file.
        One or more parameters are allowed, they are joined with os.path.join.
        Returns None on errors..
        """
        try:
            with open(os.path.join(*args)) as f:
                line = f.readline().strip()
            return line
        except __HOLE__:
            return None
dataset/ETHPy150Open pyserial/pyserial/serial/tools/list_ports_linux.py/SysFS.read_line