type Diff<T extends string, U extends string> = ({[P in T]: P} &
  {[P in U]: never} & {[x: string]: never})[T]

export type Omit<T, K extends keyof T> = Pick<T, Diff<keyof T, K>>

export type SingleOrArray<Properties, T extends keyof Properties> = {
  [P in T]: Properties[P] | Array<Properties[P]>
}