Operator '??=' cannot be applied to operands of type 'Func<TypeMappingDescriptor<T>, TypeMapping>' and 'lambda expression'

'CreateIndexRequestDescriptor' does not contain a definition for 'Map' and no accessible extension method 'Map' accepting a first argument of type 'CreateIndexRequestDescriptor' could be found (are you missing a using directive or an assembly reference?)

Operator '??=' cannot be applied to operands of type 'Func<TypeMappingDescriptor<T>, TypeMapping>' and 'lambda expression'

'CreateIndexRequestDescriptor' does not contain a definition for 'Map' and no accessible extension method 'Map' accepting a first argument of type 'CreateIndexRequestDescriptor' could be found (are you missing a using directive or an assembly reference?)

Operator '??=' cannot be applied to operands of type 'Func<CreateIndexRequestDescriptor, CreateIndexRequest>' and 'lambda expression'

Argument 2: cannot convert from 'System.Func<Elastic.Clients.Elasticsearch.IndexManagement.CreateIndexRequestDescriptor, Elastic.Clients.Elasticsearch.IndexManagement.CreateIndexRequest>' to 'System.Action<Elastic.Clients.Elasticsearch.IndexManagement.CreateIndexRequestDescriptor>'

Argument 1: cannot convert from 'System.Collections.Generic.List<Elastic.Clients.Elasticsearch.IndexName>' to 'string'

'InvertTest' does not contain a definition for 'Name' and no accessible extension method 'Name' accepting a first argument of type 'InvertTest' could be found (are you missing a using directive or an assembly reference?)

'InvertTest' does not contain a definition for 'Name' and no accessible extension method 'Name' accepting a first argument of type 'InvertTest' could be found (are you missing a using directive or an assembly reference?)

'InvertTest' does not contain a definition for 'Name' and no accessible extension method 'Name' accepting a first argument of type 'InvertTest' could be found (are you missing a using directive or an assembly reference?)

'IndicesNamespacedClient.Refresh(Indices?)' is obsolete: 'Synchronous methods are deprecated and could be removed in the future.'

'IndicesNamespacedClient.GetMapping(GetMappingRequest)' is obsolete: 'Synchronous methods are deprecated and could be removed in the future.'

'IndicesNamespacedClient.Refresh(Indices?)' is obsolete: 'Synchronous methods are deprecated and could be removed in the future.'

'IndicesNamespacedClient.GetMapping(GetMappingRequest)' is obsolete: 'Synchronous methods are deprecated and could be removed in the future.'

'IndicesNamespacedClient.Refresh(Indices?)' is obsolete: 'Synchronous methods are deprecated and could be removed in the future.'

'IndicesNamespacedClient.GetMapping(GetMappingRequest)' is obsolete: 'Synchronous methods are deprecated and could be removed in the future.'

'IndicesNamespacedClient.Refresh(Indices?)' is obsolete: 'Synchronous methods are deprecated and could be removed in the future.'

'IndicesNamespacedClient.GetMapping(GetMappingRequest)' is obsolete: 'Synchronous methods are deprecated and could be removed in the future.'

'ElasticsearchClient.Ping()' is obsolete: 'Synchronous methods are deprecated and could be removed in the future.'