How do I run a function through an arraylist?

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Java

processing

I'm using Processing 3.0.2, and I'm trying to run a function I defined in a class from an ArrayList. Processing says "The function dis() does not exist." when it obviously does.

What I have tried:

I have an ArrayList called "cs," and it contains "Circle" objects. "Circle" is a class that I made which contains a function called "dis()," and it displays the circle. I have an outside function called "discs()" (display circles) that has a for loop that's supposed to display each circle in the list. Here's what I have:

int cam_x;
int cam_y;
int mp = 0;
ArrayList cs;

void setup() {
  size(500, 500);
  cs = new ArrayList<Circle>();
}

void draw() {
  if (mousePressed && mp < 1) {
    cs.add(new Circle(mouseX,mouseY));
    mp = 1;
  } else if (!mousePressed) {
    mp = 0;
  }
  discs();
}

class Circle {
  int xa;
  int ya;
  Circle(int x,int y) {
    xa = x;
    ya = y;
  }
  
  void dis() {
    ellipseMode(CENTER);
    fill(255,0,0);
    noStroke();
    ellipse(xa, ya, 25, 25);
  }
}

void discs() {
  for (int i = 0;i<=cs.size();i++) {
    cs.get(i).dis();
  }
}

The variables cam_x/y are unused right now.