def METHOD_NAME(self):
    """
    Remove stale installed files.
    This removes files which are built/installed but which do not
    exist in the Sage sources (typically because some source file
    has been deleted). Files are removed from the build directory
    ``build/lib-*`` and from the install directory ``site-packages``.
    """
    dist = self.distribution
    cmd_build_py = self.get_finalized_command("build_py")
    cmd_build_cython = self.get_finalized_command("build_cython")
    # Determine all Python modules inside all packages
    py_modules = []
    ordinary_packages = []
    for package in dist.packages:
        package_dir = cmd_build_py.get_package_dir(package)
        if os.path.exists(os.path.join(package_dir, '__init__.py')):
            ordinary_packages.append(package)
        py_modules.extend(cmd_build_py.find_package_modules(package, package_dir))
    # modules is a list of triples (package, module, module_file).
    # Construct the complete module name from this.
    py_modules = ["{0}.{1}".format(*m) for m in py_modules]
    if dist.py_modules:
        py_modules.extend(dist.py_modules)
    # Determine all files of package data and Cythonized package files
    # example of entries of cmd_build_cython.get_cythonized_package_files():
    #   ('sage/media', ['./sage/media/channels.pyx'])
    data_files = cmd_build_cython.get_cythonized_package_files()
    # examples of entries of build_py.data_files:
    #   ('sage.libs.gap', 'sage/libs/gap', 'build/lib.macosx-10.9-x86_64-3.7/sage/libs/gap', ['sage.gaprc'])
    #   ('sage', 'sage', 'build/lib.macosx-10.9-x86_64-3.7/sage', ['ext_data/nodoctest.py', 'ext_data/kenzo/S4.txt', ...])
    nobase_data_files = [(src_dir, [os.path.join(src_dir, filename) for filename in filenames])
                         for package, src_dir, build_dir, filenames in cmd_build_py.data_files]
    # Clean install directory (usually, purelib and platlib are the same)
    # and build directory.
    output_dirs = [self.install_purelib, self.install_platlib, self.build_lib]
    from sage_setup.clean import clean_install_dir
    for output_dir in set(output_dirs):
        log.info('- cleaning {0}'.format(output_dir))
        clean_install_dir(output_dir,
                ordinary_packages,
                py_modules,
                dist.ext_modules,
                data_files,
                nobase_data_files,
                distributions=self.all_distributions)