TypeScript: `xMin`, `xMax`, `yMin`, `yMax` should accept undefined value as Scriptable options return value

[tlserver]

The four options xMin, xMax, yMin, and yMax can accept an undefined value to indicate "growth to the chart boundary." Scriptable options for these four options also support an undefined value. However, TypeScript has incorrectly defined the types for these four options:

  xMax?: Scriptable<ScaleValue, PartialEventContext>,
  xMin?: Scriptable<ScaleValue, PartialEventContext>,
  yMax?: Scriptable<ScaleValue, PartialEventContext>,
  yMin?: Scriptable<ScaleValue, PartialEventContext>,

Using (_, __) => undefined should be a valid assignment, but currently, TypeScript raises a type error.