@Override public DiagnosticMessage getUnresolvedProxyMessage(final ILinkingDiagnosticContext context) { DiagnosticMessage diagnosticMessage = new XtextSwitch<DiagnosticMessage>() { @Override public DiagnosticMessage caseRuleCall(RuleCall ruleCall) { return new DiagnosticMessage(context.getLinkText()+" cannot be resolved to a rule", Severity.ERROR, UNRESOLVED_RULE, context.getLinkText()); } }.doSwitch(context.getContext()); return diagnosticMessage != null ? diagnosticMessage : super.getUnresolvedProxyMessage(context); }