code: public static <T> String toXmlWithXStream(XStream xstream, final T objectToXML,
  		final Map<String, Class<?>> aliases)
  	{
  		if (xstream == null)
  		{
  			xstream = new XStream();
  		}
  		if (aliases != null)
  		{
  			for (final Map.Entry<String, Class<?>> alias : aliases.entrySet())
  			{
  				xstream.alias(alias.getKey(), alias.getValue());
  			}
  		}
  		final String xml = xstream.toXML(objectToXML);
  		return xml;
  	}
docs: Creates from the given Object an xml string. The given map hold the aliases. For more
  information with aliasing see documation of xstream.
  
  @param <T>
  the generic type of the return type
  @param xstream
  the xstream
  @param objectToXML
  the object to xml
  @param aliases
  the aliases
  @return the xml string