code: public void update(InputStream stream, long length, long position) throws IOException, RepositoryException
     {
        if (!changed)
        {
           internalData = createEditableCopy(this.getInternalData());
        }
  
        ((EditableValueData)internalData).update(stream, length, position);
        invalidateStream();
     }
docs: Update with <code>length</code> bytes from the specified InputStream <code>stream</code> to
  this binary value at <code>position</code>
  
  @param stream
  the data.
  @param length
  the number of bytes from buffer to write.
  @param position
  position in file to write data