code: def network_manager():
      '''
      Deals with the renaming of Quantum to Neutron in H and any situations
      that require compatability (eg, deploying H with network-manager=quantum,
      upgrading from G).
      '''
      release = os_release('nova-common')
      manager = config('network-manager').lower()
  
      if manager not in ['quantum', 'neutron']:
          return manager
  
      if release in ['essex']:
          # E does not support neutron
          log('Neutron networking not supported in Essex.', level=ERROR)
          raise Exception
      elif release in ['folsom', 'grizzly']:
          # neutron is named quantum in F and G
          return 'quantum'
      else:
          # ensure accurate naming for all releases post-H
          return 'neutronf network_manager():
      '''
      Deals with the renaming of Quantum to Neutron in H and any situations
      that require compatability (eg, deploying H with network-manager=quantum,
      upgrading from G).
      '''
      release = os_release('nova-common')
      manager = config('network-manager').lower()
  
      if manager not in ['quantum', 'neutron']:
          return manager
  
      if release in ['essex']:
          # E does not support neutron
          log('Neutron networking not supported in Essex.', level=ERROR)
          raise Exception
      elif release in ['folsom', 'grizzly']:
          # neutron is named quantum in F and G
          return 'quantum'
      else:
          # ensure accurate naming for all releases post-H
          return 'neutron'
docs: Deals with the renaming of Quantum to Neutron in H and any situations
      that require compatability (eg, deploying H with network-manager=quantum,
      upgrading from G).