code: public ApplicationDefinition getApplication(String appName) {
          checkServiceState();
          Tenant tenant = TenantService.instance().getDefaultTenant();
          return getApplicationDefinition(tenant, appName);
      }
docs: Return the {@link ApplicationDefinition} for the application in the default tenant.
  Null is returned if no application is found with the given name in the default
  tenant.
  
  @return The {@link ApplicationDefinition} for the given application or null if no
  no application such application is defined in the default tenant.
  
  @deprecated  This method only works for the default tenant. Use
  {@link #getApplication(Tenant, String)} instead.