Fix failed unit tests.

Author: mashhurs

CHANGELOG.md

@@ -1,5 +1,5 @@
 ## 4.1.1
-  - Adds elastic-transport support [#191](https://github.com/logstash-plugins/logstash-filter-elasticsearch/pull/191)
+  - Adds elastic-transport client support [#191](https://github.com/logstash-plugins/logstash-filter-elasticsearch/pull/191)
 
 ## 4.1.0
  - Added support for custom headers [#188](https://github.com/logstash-plugins/logstash-filter-elasticsearch/pull/188)

spec/filters/elasticsearch_spec.rb

@@ -103,6 +103,7 @@
 
     before(:each) do
       allow(LogStash::Filters::ElasticsearchClient).to receive(:new).and_return(client)
+      allow(client).to receive(:es_transport_client_type).and_return('elasticsearch_transport')
       allow(client).to receive(:search).and_return(response)
       allow(plugin).to receive(:test_connection!)
       allow(plugin).to receive(:setup_serverless)
@@ -347,6 +348,7 @@
 
       before do
         allow(plugin).to receive(:get_client).and_return(client_double)
+        allow(client_double).to receive(:es_transport_client_type).and_return('elasticsearch_transport')
         allow(client_double).to receive(:client).and_return(transport_double)
       end
 
@@ -821,6 +823,7 @@ def wait_receive_request
 
     before(:each) do
       allow(LogStash::Filters::ElasticsearchClient).to receive(:new).and_return(client)
+      allow(client).to receive(:es_transport_client_type).and_return('elasticsearch_transport')
       allow(plugin).to receive(:test_connection!)
       allow(plugin).to receive(:setup_serverless)
       plugin.register