Allows representation of XML documents as Java Objects.
An instance of ParameterValue represents an XML Instance to which can be
added XML elements (see org.ws4d.java.schema). XML Instances are used to define a WSDL message content (see org.ws4d.java.wsdl).
ParameterValue instances are notably used as arguments and return types of Operation instances
(see org.ws4d.java.service Operation)
The ParameterAttribute class is used within a ParameterValue instance to represent XML attributes