import com.sun.xml.internal.dtdparser.DTDEventListener; //导入依赖的package包/类
private CClassInfo calcClass() {
    BIElement e = owner.bindInfo.element(name);
    if(e==null) {
        if(contentModelType!=DTDEventListener.CONTENT_MODEL_MIXED
        || !attributes.isEmpty()
        || mustBeClass)
            return createDefaultClass();
        if(contentModel!=Term.EMPTY) {
            throw new UnsupportedOperationException("mixed content model not supported");
        } else {
            // just #PCDATA
            if(isReferenced)
                return null;
            else
                // if no one else is referencing, assumed to be the root.
                return createDefaultClass();
        }
    } else {
        return e.clazz;
    }
}
 

import com.sun.xml.internal.dtdparser.DTDEventListener; //导入依赖的package包/类
static Term wrap( Term t, int occurence ) {
    switch(occurence) {
    case DTDEventListener.OCCURENCE_ONCE:
        return t;
    case DTDEventListener.OCCURENCE_ONE_OR_MORE:
        return new Occurence(t,false,true);
    case DTDEventListener.OCCURENCE_ZERO_OR_MORE:
        return new Occurence(t,true,true);
    case DTDEventListener.OCCURENCE_ZERO_OR_ONE:
        return new Occurence(t,true,false);
    default:
        throw new IllegalArgumentException();
    }
}