@Override
		public boolean equals(Object obj){
			if (this == obj)
	    		return true;
	    	if (obj == null)
	    		return false;
	    	if (getClass() != obj.getClass())
	    		return false;
	    	MyString other = (MyString) obj;
	    	if (str == null) {
	    		if (other.str != null)
	    			return false;
	    	} else if (!str.equals(other.str))
	    		return false;
	    	return true;
		}