docs: def hostname(self, levels=1):
          """
          Produce a hostname with specified number of subdomain levels.
  
          >>> hostname()
          db-01.nichols-phillips.com
          >>> hostname(0)
          laptop-56
          >>> hostname(2)
          web-12.williamson-hopkins.jackson.com
          """
          if levels < 1:
              return self.random_element(self.hostname_prefixes) + '-' + self.numerify('##')
          return self.random_element(self.hostname_prefixes) + '-' + self.numerify('##') + '.' + self.domain_name(levels)