code: @Nonnull
    public String getContentAsString ()
    {
      if (m_sContent == null)
        m_sContent = new String (m_aContent, m_aCharset);
      return m_sContent;
    }
docs: Get the data content of this Data URL as String. If no String
  representation was provided in the constructor, than it is lazily created
  inside this method in which case instances of this class are not
  thread-safe. If a non-<code>null</code> String was provided in the
  constructor, this object is immutable. No Base64 encoding is performed in
  this method.
  
  @return The content in a String representation using the charset of this
  object. Never <code>null</code>.