docs: def _get_authz_session(self):
          """Gets the AuthorizationSession for the default (bootstrap) typed Vault
  
          Assumes only one vault of this Type, but it can have children depending on underlying impl.
  
          """
          from ..utilities import BOOTSTRAP_VAULT_TYPE
          try:
              vaults = self._get_vault_lookup_session().get_vaults_by_genus_type(BOOTSTRAP_VAULT_TYPE)
          except Unimplemented:
              return self._get_authz_manager().get_authorization_session()
          if vaults.available():
              vault = vaults.next()
              return self._get_authz_manager().get_authorization_session_for_vault(vault.get_id())
          else:
              return self._get_authz_manager().get_authorization_session()