This class represents a table of all of the top-level symbols from a set of WSDL Definitions and
DOM Documents: XML types; WSDL messages, portTypes, bindings, and services.
This symbolTable contains entries of the form where key is of type QName and value is
of type Vector. The Vector's elements are all of the objects that have the given QName. This is
necessary since names aren't unique among the WSDL types. message, portType, binding, service,
could all have the same QName and are differentiated merely by type. SymbolTable contains
type-specific getters to bypass the Vector layer:
public PortTypeEntry getPortTypeEntry(QName name), etc.
