Alter Textfield functionality ControlP5

I would like to remove some of the functionality of a Textfield.

When the enter or return keys are pressed, the field becomes empty. I would like the value entered to stay within the field.

I have tried overriding the submit method but this hasn't done the job:

widthTopField = new Textfield(controlP5, "widthField"){
    @ Override public Textfield submit(){
        return this;
    }
};

Demonstrates using .setAutoClear() to retain edit field contents after hitting return button. Field 1 is set to true and the other is set to false.

import controlP5.*;

ControlP5 cp5;

void setup() {
  size(400,400);
  
  PFont font = createFont("arial",18);
  
  cp5 = new ControlP5(this);
  
  cp5.addTextfield("Field 1")
     .setPosition(40,50)
     .setSize(200,40)
     .setFont(font)
     .setFocus(true)
     .setColor(color(255))
     .setAutoClear(true);
     ;
                 
  cp5.addTextfield("Field 2")
     .setPosition(40,130)
     .setSize(200,40)
     .setFont(font)
     .setAutoClear(false);
     ;
}

void draw() {
  background(0);
}