capacity() StringBuffer method in java

/**
 * This program is used to show the use of capacity() method.
 * @author w3spoint
 */
class TestStringBuffer{
	StringBuffer sb = new StringBuffer();
 
	/**
	 * This method is used to show the use of capacity() method.
	 * @author w3spoint
	 */
	public void capacityTest(){
		//default capacity.
		System.out.println(sb.capacity());
 
		sb.append("Hello ");
		//current capacity 16.
		System.out.println(sb.capacity());
 
		sb.append("www.w3spoint.com");
		//current capacity (16*2)+2=34 i.e (oldcapacity*2)+2.  
		System.out.println(sb.capacity());
	}
}
 
public class StringBufferCapacityExample {
	public static void main(String args[]){
		//creating TestStringBuffer object
		TestStringBuffer obj = new TestStringBuffer();
 
		//method call
		obj.capacityTest();
	}
}

16
16
34