DTSPB-4818 remove no-use code

Author: MarcusHMCTS

src/test/java/uk/gov/hmcts/probate/client/ResponseDecoratorTest.java

@@ -16,7 +16,6 @@
 
 import java.io.IOException;
 import java.io.InputStream;
-import java.lang.reflect.Field;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashMap;
@@ -46,9 +45,6 @@ public void bodyToStringShouldReturnString() throws ReflectiveOperationException
                 .build();
 
         ResponseDecorator responseDecorator = new ResponseDecorator(response,objectMapper);
-        Field objectMapperField = ResponseDecorator.class.getDeclaredField("objectMapper");
-        objectMapperField.setAccessible(true);
-        objectMapperField.set(responseDecorator, objectMapper);
         String body = responseDecorator.bodyToString();
 
         assertThat(body).isEqualTo("hello world");