‘editor.action.triggerSuggest’ will trigger the 'provideCompletionItemsmethod' twice

[xinshemeigui]

monaco-editor version: 0.20.0
**Browser:chrome
**OS:win10
Playground code that reproduces the issue:

self.monacoInstance.onKeyDown(e => {
        if (e.keyCode === 1) {
          if (self.monacoInstance.getValue()) {
            self.monacoInstance.trigger('', 'editor.action.triggerSuggest', {})
          }
        }
      })

When I press BackSpace ‘provideCompletionItems’ will be triggered twice
Trigger once before the value changes
Trigger once when the value changes
But I just want him to trigger it a second time
What should I do?