Simple XML Creator in Java
What's this?

public XMLCreator() {
    if (this.xml == null) {
        this.xml = new HashMap&lt;Integer, String&gt;();
    }
    if (this.roots == null) {
        this.roots = new HashMap&lt;Integer, String&gt;();
    }
    if (this.sB == null) {
        this.sB = new StringBuilder();
    }
}


The null checks are always true, where should a value come from?

Why 

this.child = "&lt;" + child + "&gt;" + "&lt;/" + child + "&gt;";


and not 

this.child = "&lt;" + child + "/&gt;";


?