NXTShield MX

Hi,

I’m trying to use NXTShield MX on Arduino Mega.

I have to read a register which returns to me the NXTShield battery voltage.
This is my code

#include <Wire.h>
#include <NXShield.h>
#include <NXShieldI2C.h>


NXShield         nxshield;
NXShieldI2C      Shield();



int a;



void setup() {
  
  Serial.begin(9600);

  nxshield.init( SH_SoftwareI2C );

  Serial.println ("Press GO button to continue");
  nxshield.waitForButtonPress(BTN_GO);

}

void loop() {

  a = Shield.readByte(0x41);

  Serial.println(a);
  
  delay(1000);
}

The error is: error: request for member ‘readByte’ in ‘Shield’, which is of non-class type ‘NXShieldI2C ()()’

Here the documentation of the library: http://www.openelectrons.com/NXShield/html/class_n_x_shield_i2_c.html#a1cff5922dedb607a0b40097b47a66013

What am I doing wrong?

Thanks.