class_declaration ::= // from Annex A.1.3
[ virtual ] class [ lifetime ] class_identifier
[ parameter_port_list ]
[ extends class_identifier [parameter_value_assignment
] [ ( list_of_arguments) ] ] ;
{ class_item }
endclass [ : class_identifier]
Identifiers on the left
side of the scope-resolution operator (::) can be only
class names or package names (see Section 18.2).