I can't implement TreeNode with generics because of the getChildren() method.

I have the following class:

public class SystemTreeNode implements TreeNode<Integer> {

 private Integer data;
 private Map<Object, SystemTreeNode> childrensMap;

 public Iterator<Map.Entry<Object, TreeNode<Integer>>> getChildren() {
 return childrensMap.entrySet().iterator();
 }
 .
 .
 .
}

And it does not compile with the following error:

found : java.util.Iterator<java.util.Map.Entry<java.lang.Object,com.xeround.xms.ui.tree.SystemTreeNode>>
required: java.util.Iterator<java.util.Map.Entry<java.lang.Object,org.richfaces.model.TreeNode<java.lang.Integer>>>

I can change the childrensMap var to

Map<Object, TreeNode<Integer>> childrensMap;

but this is not good enough.

How can this be done?