src/vs/workbench/contrib/outline/browser/outlinePane.ts/OutlinePane/_handleEditorChanged
class OutlinePane:	private _handleEditorChanged(pane: IEditorPane | undefined): void {
		this._editorPaneDisposables.clear();

		if (pane) {
			// react to control changes from within pane (https://github.com/microsoft/vscode/issues/134008)
			this._editorPaneDisposables.add(pane.onDidChangeControl(() => {
				this._handleEditorControlChanged(pane);
			}));
		}

		this._handleEditorControlChanged(pane);
	}