This type is an alias for the Partial<T> TypeScript utility type. It makes all properties of an Object optional.
Example usage is shown below.
const T = Type.Object({ // const T: TObject<{
x: Type.Number(), // x: TNumber,
y: Type.Number(), // y: TNumber,
z: Type.Number() // z: TNumber
}) // }>
const S = Type.Partial(T) // const S: TObject<{
// x: TOptional<TNumber>,
// y: TOptional<TNumber>,
// z: TOptional<TNumber>
// }>