I created an interface with abstract methods.

public interface PropertyFileSectionData
{
   public abstract String getSectionName();
   public abstract void setSectionName(String sectionName);

   public abstract String getSectionComment();
   public abstract void setSectionComment(String sectionComment);

   public abstract PropertyFilePropAndValuePairsData
getPropertyAndValuePairs();
   public abstract void
setPropertyAndValuePairs(PropertyFilePropAndValuePairsData
propAndVauePairs);

}

I also create an implementation class to actually do the work.

public class PropertyFileSectionDataImpl implements
PropertyFileSectionData
{
   protected String _sectionName;
   protected String _sectionComment;
   protected  SPPropertyFilePropAndValuePairsData _propAndValuePairs;

       public PropertyFilePropAndValuePairsData
getPropertyAndValuePairs()  {
       return _propAndValuePairs;
   }
      public void
setPropertyAndValuePairs(PropertyFilePropAndValuePairsData
andValuePairs)   {
       _propAndValuePairs = andValuePairs;
   }
      public String getSectionComment()  {
       return _sectionComment;
   }
      public void setSectionComment(String comment)   {
       _sectionComment = comment;
   }
      public String getSectionName()   {
       return _sectionName;
   }
     public void setSectionName(String name)  {
       _sectionName = name;
   }
}