':py:class:`X509Extension` accepts an extension type name, a critical flag,
and an extension value and returns an :py:class:`X509ExtensionType` instance.'

def test_construction(self):

    basic = X509Extension(b('basicConstraints'), True, b('CA:true'))
    self.assertTrue(isinstance(basic, X509ExtensionType), ('%r    is    of    type    %r,    should    be    %r' % (basic, type(basic), X509ExtensionType)))
    comment = X509Extension(b('nsComment'), False, b('pyOpenSSL    unit    test'))
    self.assertTrue(isinstance(comment, X509ExtensionType), ('%r    is    of    type    %r,    should    be    %r' % (comment, type(comment), X509ExtensionType)))
