code: def resources_availability(self):
          
          # Flatten the list.
          availabilities = list(
              chain(
                  *[org.check_availability() for org in self.organizations]
              )
          )
          # Filter out the unknown
          availabilities = [a for a in availabilities if type(a) is bool]
          if availabilities:
              # Trick will work because it's a sum() of booleans.
              return round(100. * sum(availabilities) / len(availabilities), 2)
          # if nothing is unavailable, everything is considered OK
          return 100
docs: Return the percentage of availability for resources.