Extends the 
  Document interface with additional methods for both 
  document and CM
   editing. 
IDL:
interface DocumentCM : Document {
  int                numCMs();
  CMModel            getInternalCM();
  CMExternalModel *  getCMs();
  CMModel            getActiveCM();
  void               addCM(in CMModel cm);
  void               removeCM(in CMModel cm);
  boolean            activateCM(in CMModel cm);
};
Java binding:
package org.w3c.dom.contentModel;
public interface DocumentCM extends Document {
    public int             numCMs();
    public CMModel         getInternalCM();
    public CMExternalModel getCMs();
    public CMModel         getActiveCM();
    public void            addCM(CMModel cm);
    public void            removeCM(CMModel cm);
    public boolean         activateCM(CMModel cm);
}