Different threads calling same method at same time

package com.javahonk.multipleextends;

public class ThreadTestString {

	String value2 ="ABC";

	public static void main(String[] args) {
		final ThreadTestString testString = new ThreadTestString();
		Runnable t1 = new Runnable() {
	        public void run() {
	        	testString.m1("123","A");
	        }
	    };

	    Runnable t2 = new Runnable() {
	        public void run() {
	        	testString.m1("DEF","B");

	        }
	    };

	    new Thread(t1).start();
	    new Thread(t2).start();

	}

	void m1(String value , String collar){

		value2=value;		
		for (int i = 0; i < 25000; i++) {
			System.out.println("Collar: "+collar+" value: "+value2);
		}
	}

}