[demo] Add missing KnockoutObservable<T>
@@ -22,6 +22,8 @@ interface SqlScratchpadState {
executor?: Executor;
}
+type KnockoutObservable<T> = () => T;
+
export class SqlScratchpad extends React.Component<{}, SqlScratchpadState> {
state = {
activeExecutable: undefined,
