code: private void addGetter(final TypeSpec.Builder classBuilder, final String attributeName, final TypeName type) {
          final String getterMethodName = "get" + attributeName.substring(0, 1).toUpperCase() + attributeName.substring(1);
          final MethodSpec.Builder getterBuilder = MethodSpec.methodBuilder(getterMethodName);
          getterBuilder.returns(type);
          getterBuilder.addModifiers(Modifier.PUBLIC);
          getterBuilder.addCode("return this." + attributeName + ";");
  
          classBuilder.addMethod(getterBuilder.build());
      }
docs: adds getter for field to class
  @param classBuilder class to modify
  @param attributeName name of attribute to be referenced
  @param type type of attribue to be referenced