def build_extension(self, ext):
    if (ext.language == 'java'):
        return self.build_java_ext(ext)
    if self.jar:
        return
    print('Call build ext')
    return super().build_extension(ext)
def build_extension(self, ext):
    if (ext.language == 'java'):
        return self.build_java_ext(ext)
    if self.jar:
        return
    print('Call build ext')
    return super().build_extension(ext)