extensions/references-view/src/references/model.ts/ReferenceItem/getDocument
class ReferenceItem:	async getDocument(warmUpNext?: boolean) {
		if (!this._document) {
			this._document = vscode.workspace.openTextDocument(this.location.uri);
		}
		if (warmUpNext) {
			// load next document once this document has been loaded
			const next = this.file.model.next(this.file);
			if (next instanceof FileItem && next !== this.file) {
				vscode.workspace.openTextDocument(next.uri);
			} else if (next instanceof ReferenceItem) {
				vscode.workspace.openTextDocument(next.location.uri);
			}
		}
		return this._document;
	}