diff -up ./src/org/apache/html/dom/HTMLFrameElementImpl.java.fix ./src/org/apache/html/dom/HTMLFrameElementImpl.java
--- ./src/org/apache/html/dom/HTMLFrameElementImpl.java.fix	2018-04-21 00:02:12.000000000 -0400
+++ ./src/org/apache/html/dom/HTMLFrameElementImpl.java	2020-06-24 13:22:17.584233178 -0400
@@ -17,6 +17,7 @@
 package org.apache.html.dom;
 
 import org.w3c.dom.html.HTMLFrameElement;
+import org.w3c.dom.Document;
 
 /**
  * @xerces.internal
@@ -137,7 +138,10 @@ public class HTMLFrameElementImpl
     {
         super( owner, name );
     }
-  
+
+    public Document getContentDocument() {
+        return super.getOwnerDocument();
+    }
 
 }
 
diff -up ./src/org/apache/html/dom/HTMLIFrameElementImpl.java.fix ./src/org/apache/html/dom/HTMLIFrameElementImpl.java
--- ./src/org/apache/html/dom/HTMLIFrameElementImpl.java.fix	2018-04-21 00:02:12.000000000 -0400
+++ ./src/org/apache/html/dom/HTMLIFrameElementImpl.java	2020-06-24 13:22:37.686198652 -0400
@@ -17,6 +17,7 @@
 package org.apache.html.dom;
 
 import org.w3c.dom.html.HTMLIFrameElement;
+import org.w3c.dom.Document;
 
 /**
  * @xerces.internal
@@ -161,6 +162,9 @@ public class HTMLIFrameElementImpl
         super( owner, name );
     }
 
+    public Document getContentDocument() {
+        return super.getOwnerDocument();
+    }
 
 }
 
diff -up ./src/org/apache/html/dom/HTMLObjectElementImpl.java.fix ./src/org/apache/html/dom/HTMLObjectElementImpl.java
--- ./src/org/apache/html/dom/HTMLObjectElementImpl.java.fix	2018-04-21 00:02:09.000000000 -0400
+++ ./src/org/apache/html/dom/HTMLObjectElementImpl.java	2020-06-24 13:23:01.294158104 -0400
@@ -17,6 +17,7 @@
 package org.apache.html.dom;
 
 import org.w3c.dom.html.HTMLObjectElement;
+import org.w3c.dom.Document;
 
 /**
  * @xerces.internal
@@ -251,6 +252,9 @@ public class HTMLObjectElementImpl
         super( owner, name );
     }
 
+    public Document getContentDocument() {
+        return super.getOwnerDocument();
+    }
 
 }