'This extension is used to determine if the subject of the certificate
is a CA, and if so, what the maximum number of intermediate CA certs
after this are, before an end-entity certificate is found.
:return:
None or a BasicConstraints object'

@property
def basic_constraints_value(self):

    if (not self._processed_extensions):
        self._set_extensions()
    return self._basic_constraints_value
