A parameter or return value may be represented as an attachment.
In such cases, the ParameterDescription or OperationDescription has
an AttachmentDescription defining the attachment information.
Note that an Attachment may be one of 3 types: SWA, SWAREF and MTOM.
SWAREF and MTOM attachments have an xml element (either in the body or header)
that references the attachment part.
SWA attachments are represented as an attachment part.
Creates the JAX-WS metadata descritpion hierachy from some combinations of WSDL, Java class
information including annotations, and (in the future) deployment descriptors.
A ServiceDescription corresponds to a Service under which there can be a collection of enpdoints.
In WSDL 1.1 terms, then, a ServiceDescription corresponds to a wsdl:Service under which there are
one or more wsdl:Port entries.