'Install a module from an egg file by unzipping the necessary parts
into install_dir.
:param install_dir - The installation directory.
:param egg_path - The pathname of the egg file.'

def _install_from_egg(self, install_dir, egg_path):

    status = system(("unzip    -q    -o    -d    '%s'    '%s'" % (install_dir, egg_path)))
    if status:
        logging.error('unzip    of    %s    failed', egg_path)
        return False
    egg_info = os.path.join(install_dir, 'EGG-INFO')
    if os.path.isdir(egg_info):
        shutil.rmtree(egg_info)
    return True
