code: protected void writeArrayOutParamsToProxy(VariableElement param, MethodSpec.Builder methodBuilder) {
          methodBuilder.beginControlFlow("if (" + param.getSimpleName() + " == null)");
          methodBuilder.addStatement("data.writeInt(-1)");
          methodBuilder.endControlFlow();
          methodBuilder.beginControlFlow("else");
          methodBuilder.addStatement("data.writeInt(" + param.getSimpleName() + ".length)");
          methodBuilder.endControlFlow();
      }
docs: Called to generate code that writes the out params for array type