Code example for TreeMap

		if (result == null) throw new ElementNotFoundException(name); 
		return result; 
	} 
	 
	public Element[] getAll(){ 
		return contents.values().toArray(new Element[contents.size()]); 
	} 
	 
	public int size(){ 
		return contents.size(); 
	} 
	 
	public static ElementTable generateCHNOPS(){ 
		ElementTable et = new ElementTable(); 
		et.add(new Element("C", 12.0, 4)); 
		et.add(new Element("H", 1.007825, 1)); 
		et.add(new Element("N", 14.003074, 3)); 
		et.add(new Element("O", 15.994915, 2)); 
		et.add(new Element("P", 30.973762, 3)); 
		et.add(new Element("S", 31.972071, 2));