def add(self, *filenames):
        """
        If the dependency `filename` has not already been added,
        append it to self.list and print it to self.file if self.file
        is not None.
        """
        for filename in filenames:
            if not filename in self.list:
                self.list.append(filename)
                if self.file is not None:
                    print >>self.file, filename
dataset/ETHPy150Open adieu/allbuttonspressed/docutils/utils.py/DependencyList.add/original