code: def do_show(self, option, single=None):
          
          headers = []
          rows = []
          align = None
          # show clusters
          if option == "clusters":
              "Display list of clusters on system"
              headers = ["CLUSTER NAME"]
              clusters = api.get_all_clusters()
              for cluster in clusters:
                  rows.append([cluster.name])
  
          # show hosts
          if option == "hosts":
              "Display a list of hosts avaiable on the system"
              headers = ["HOSTNAME", "IP ADDRESS", "RACK"]
              align = ["HOSTNAME", "IP ADDRESS", "RACK"]
              for host in api.get_all_hosts():
                  rows.append([host.hostname, host.ipAddress, host.rackId])
  
          # show services
          if option == "services":
              "Show list of services on the cluster"
              headers = ["NAME", "SERVICE", "STATUS", "HEALTH", "CONFIG"]
              align = ["NAME", "SERVICE"]
  
              # Check if the user has selected a cluster
              if not self.has_cluster():
                  print("Error: Please select a cluster first")
                  return None
  
              if not single:
                  for s in api.get_cluster(self.cluster).get_all_services():
                      if s.configStale:
                          config = "STALE"
                      else:
                          config = "UP TO DATE"
                      rows.append([s.name, s.type, s.serviceState, s.healthSummary, config])
              else:
                  s = api.get_cluster(self.cluster).get_service(single)
                  if s.configStale:
                      config = "STALE"
                  else:
                      config = "UP TO DATE"
                  rows.append([s.name, s.type, s.serviceState, s.healthSummary, config])
  
          self.generate_output(headers, rows, align=align)
docs: General System Information
          Usage:
              > show clusters     list of clusters this CM manages
              > show hosts        list of all hosts CM manages
              > show services     list of all services on this cluster
                                  including their health.