src/vs/workbench/browser/parts/views/viewPaneContainer.ts/ViewPaneContainer/removePane
class ViewPaneContainer:	private removePane(pane: ViewPane): void {
		const index = this.paneItems.findIndex(i => i.pane === pane);

		if (index === -1) {
			return;
		}

		if (this.lastFocusedPane === pane) {
			this.lastFocusedPane = undefined;
		}

		assertIsDefined(this.paneview).removePane(pane);
		const [paneItem] = this.paneItems.splice(index, 1);
		paneItem.disposable.dispose();

	}