'Return the list of \'effective\' :term:`principal` identifiers
for the ``request``. If no :term:`authentication policy` is in effect,
this will return a one-element list containing the
:data:`pyramid.security.Everyone` principal.
.. versionadded:: 1.5'

@property
def effective_principals(self):

    policy = self._get_authentication_policy()
    if (policy is None):
        return [Everyone]
    return policy.effective_principals(self)
