Begin working on making there be per-subtype classes for class methods

module/documents/Actor/Handler.mjs

@@ -0,0 +1,22 @@
+import { PlayerActor } from "./Player.mjs";
+
+export class ActorHandler extends Actor {
+	actorTypes = {
+		player: PlayerActor,
+	};
+
+	constructor(data, ctx) {
+		super(data, ctx);
+	};
+
+	/** @type {class|undefined} */
+	get fn() {
+		return this.actorTypes[this.type];
+	};
+
+	createCustomSpell() {
+		if (!this.fn?.createCustomSpell) return;
+		this.fn.createCustomSpell.bind(this)();
+		this.sheet.render(true);
+	};
+};

module/documents/Actor/Player.mjs

@@ -0,0 +1,10 @@
+export class PlayerActor {
+	static createCustomSpell() {
+		let customUUID = `Spell.Custom.${randomID()}`;
+		this.system.spells[customUUID] = {
+			name: ``,
+			cost: ``,
+			description: ``,
+		};
+	};
+};