src/vs/workbench/browser/parts/editor/editorGroupView.ts/EditorGroupView/doCloseEditor
class EditorGroupView:	private doCloseEditor(editor: EditorInput, focusNext = (this.accessor.activeGroup === this), internalOptions?: IInternalEditorCloseOptions): void {
		let index: number | undefined;

		// Closing the active editor of the group is a bit more work
		if (this.model.isActive(editor)) {
			index = this.doCloseActiveEditor(focusNext, internalOptions);
		}

		// Closing inactive editor is just a model update
		else {
			index = this.doCloseInactiveEditor(editor, internalOptions);
		}

		// Forward to title control unless skipped via internal options
		if (!internalOptions?.skipTitleUpdate) {
			this.titleAreaControl.closeEditor(editor, index);
		}
	}