def add_defaults(self):
        """Add all the default files to self.filelist:
          - README or README.txt
          - setup.py
          - tests/test*.py and test/test*.py
          - all pure Python modules mentioned in setup script
          - all files pointed by package_data (build_py)
          - all files defined in data_files.
          - all files defined as scripts.
          - all C sources listed as part of extensions or C libraries
            in the setup script (doesn't catch C headers!)
        Warns if (README or README.txt) or setup.py are missing; everything
        else is optional.
        """
        self._add_defaults_standards()
        self._add_defaults_optional()
        self._add_defaults_python()
        self._add_defaults_data_files()
        self._add_defaults_ext()
        self._add_defaults_c_libs()
        self._add_defaults_scripts()
Add all the default files to self.filelist:
          - README or README.txt
          - setup.py
          - tests/test*.py and test/test*.py
          - all pure Python modules mentioned in setup script
          - all files pointed by package_data (build_py)
          - all files defined in data_files.
          - all files defined as scripts.
          - all C sources listed as part of extensions or C libraries
            in the setup script (doesn't catch C headers!)
        Warns if (README or README.txt) or setup.py are missing; everything
        else is optional.
        
product/gradle-plugin/src/main/python/setuptools/_distutils/command/sdist.py