def find_swig(self):
        """Return the name of the SWIG executable.  On Unix, this is
        just "swig" -- it should be in the PATH.  Tries a bit harder on
        Windows.
        """
        if os.name == "posix":
            return "swig"
        elif os.name == "nt":
            # Look for SWIG in its standard installation directory on
            # Windows (or so I presume!).  If we find it there, great;
            # if not, act like Unix and assume it's in the PATH.
            for vers in ("1.3", "1.2", "1.1"):
                fn = os.path.join("c:\\swig%s" % vers, "swig.exe")
                if os.path.isfile(fn):
                    return fn
            else:
                return "swig.exe"
        else:
            raise DistutilsPlatformError(
                "I don't know how to find (much less run) SWIG "
                "on platform '%s'" % os.name
            )
Return the name of the SWIG executable.  On Unix, this is
        just "swig" -- it should be in the PATH.  Tries a bit harder on
        Windows.
        
product/gradle-plugin/src/main/python/setuptools/_distutils/command/build_ext.py