code: public Collection<Tenant> getTenants() {
          checkServiceState();
          Map<String, TenantDefinition> tenantMap = getAllTenantDefs();
          List<Tenant> result = new ArrayList<>();
          for (String tenantName : tenantMap.keySet()) {
              result.add(new Tenant(tenantMap.get(tenantName)));
          }
          return result;
      }
docs: Get the list of all known tenants. Each {@link Tenant} object contains the
  corresponding tenant's {@link TenantDefinition}.
  
  @return  List of all known {@link Tenant}.