def _is_cert(item):
    """
    Returns True if a given CFTypeRef is a certificate.
    """
    expected = Security.SecCertificateGetTypeID()
    return CoreFoundation.CFGetTypeID(item) == expected

    Returns True if a given CFTypeRef is a certificate.
    
product/gradle-plugin/src/main/python/pip/_vendor/urllib3/contrib/_securetransport/low_level.py