openspec test fixup

Author: picandocodigo

elasticsearch-api/spec/unit/perform_request_spec.rb

@@ -50,6 +50,16 @@
       end
     end
 
+    let(:transport_double) do
+      Transport ||= Struct.new('Transport', :options)
+      Transport.new({ transport_options: { headers: {} } })
+    end
+
+    before do
+      allow(client_double).to receive(:transport).and_return transport_double
+      allow(Elasticsearch::API::Utils).to receive(:update_ndjson_headers!).and_return(headers)
+    end
+
     let(:response_double) do
       double('response', status: 200, body: {}, headers: {})
     end