'package : str, optional
The name of a specific package to test, e.g. \'io.fits\' or \'utils\'.
If nothing is specified all default Astropy tests are run.'

@keyword(priority=1)
def package(self, package, kwargs):

    if (package is None):
        self.package_path = self.base_path
    else:
        self.package_path = os.path.join(self.base_path, package.replace(u'.', os.path.sep))
        if (not os.path.isdir(self.package_path)):
            raise ValueError(u'Package    not    found:    {0}'.format(package))
    if (not kwargs[u'test_path']):
        return [self.package_path]
    return []
