PDFBOX-5660: improve javadoc

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1921686 13f79535-47bb-0310-9956-ffa450edef68

pdfbox/src/main/java/org/apache/pdfbox/pdmodel/documentinterchange/logicalstructure/PDStructureNode.java

@@ -144,7 +144,7 @@ public void setKids(List<Object> kids)
     }
 
     /**
-     * Appends a structure element kid.
+     * Appends a structure element kid and sets the parent property (/P) to this.
      * 
      * @param structureElement the structure element
      */
@@ -270,10 +270,10 @@ protected void insertBefore(COSBase newKid, Object refKid)
     }
 
     /**
-     * Removes a structure element kid.
-     * 
+     * Removes a structure element kid and if successful also removes the parent property (/P).
+     *
      * @param structureElement the structure element
-     * @return <code>true</code> if the kid was removed, <code>false</code> otherwise
+     * @return <code>true</code> if the kid was removed, <code>false</code> otherwise.
      */
     public boolean removeKid(PDStructureElement structureElement)
     {