public override void PostWalkTaskNodeDeclaration(TaskNodeDeclarationSyntax taskNodeDeclarationSyntax) { 
			MethodsCalled["PostWalkTaskNodeDeclaration"]=true;
		}
        public override void VisitTaskNodeDeclaration(TaskNodeDeclarationSyntax taskNodeDeclarationSyntax) {

            var taskIdentifier = taskNodeDeclarationSyntax.Identifier;
            var taskAlias      = taskNodeDeclarationSyntax.IdentifierAlias;
            var nodeIdentifier = taskAlias.IsMissing ? taskIdentifier : taskAlias;

            if (nodeIdentifier.IsMissing) {
                // Diesen Fall haben wir, wenn nur "task ;" eingegeben wird. Dafür gibt es aber bereits einen Syntax Fehler.
                return;
            }
            
            TaskNodeAliasSymbol taskNodeAlias = null;
            if (!taskAlias.IsMissing) {
                var aliasName     = taskAlias.ToString();
                var aliasLocation = taskAlias.GetLocation();
                taskNodeAlias     = new TaskNodeAliasSymbol(aliasName, aliasLocation);
            }
            
            var taskName        = taskIdentifier.ToString();
            var taskLocation    = taskIdentifier.GetLocation();
            var taskDeclaration = _taskDeklarations.TryFindSymbol(taskName);

            var taskNode = new TaskNodeSymbol(taskName, taskLocation, taskNodeDeclarationSyntax, taskNodeAlias, taskDeclaration, _taskDefinition);

            if(taskNode.Declaration == null) {
                if(taskLocation != null) {
                    _diagnostics.Add(new Diagnostic(
                        taskLocation, 
                        DiagnosticDescriptors.Semantic.Nav0010CannotResolveTask0, 
                        taskName));
                }
            } else {
                taskNode.Declaration.References.Add(taskNode);
            }
            
            AddNodeDeclaration(taskNode);            
        }
		// TaskNodeDeclarationSyntax
		public override bool WalkTaskNodeDeclaration(TaskNodeDeclarationSyntax taskNodeDeclarationSyntax) { 
			MethodsCalled["WalkTaskNodeDeclaration"]=true;
			return true; 
		}