IExternalCodeCompletionData
                        interface IExternalCodeCompletionData
                    
                    This interface is essentially the same as ICompletionData from AvalonEdit 
            except it does not include any references to WPF.
            
The CompletionType this completionData represents.
            
The displayed content. This can be the same as 'Text', or a WPF UIElement if
                you want to display rich content.
            
Gets the description.
            
Gets the priority. This property is used in the selection logic. You can use
              it to prefer selecting those items which the user is accessing most frequently.
            
Gets the text. This property is used to filter the list of visible elements.