Adding Methods to a Union of Classes in TypeScript

import { Match, Schema } from "effect";

class VolumeMuted extends Schema.Class<VolumeMuted>("VolumeMuted")({}) {
  readonly _tag = "VolumeMuted";
}

class VolumeSet extends Schema.Class<VolumeSet>("VolumeSet")({
  volume: Schema.Number.check(Schema.isBetween({ minimum: 0, maximum: 100 }))
}) {
  readonly _tag = "VolumeSet";
}

const VolumeUnion = Schema.Union([VolumeSet, VolumeMuted]);
type VolumeUnion = typeof VolumeUnion.Type

// CAN I DO THIS?!?!
class VolumeUnionSchema extends Schema.Union([VolumeSet, VolumeMuted]) {
  readonly _tag = "VolumeUnion";

  isMuted(): boolean {
    return Match.valueTags(this, {
      VolumeSet: (v) => v.volume === 0,
      VolumeMuted: () => true
    });
  }
}