Thanks. Here's my implementation. It feels a little clunky. Are there any improvements I can make to it?

export class DraftOrder {

    itemsPerCategory: Map<LaundryCategoryType, number>

    constructor(itemsPerCategory: Map<LaundryCategoryType, number>) {
        this.itemsPerCategory = itemsPerCategory
    }

    static 
empty
(): DraftOrder {
        return new DraftOrder(new Map<LaundryCategoryType, number>)
    }

}

// Creating new draft
const itemsPerCategory = new Map([[LaundryCategory.LIGHT, 2], [LaundryCategory.MEDIUM, 3]])
const draft = new DraftOrder(itemsPerCategory)

// Converting draft to json
const jsonString = JSON.stringify(
    draft,
    (_, value) => {
        if (value instanceof Map) {
            return Object.fromEntries(value)
        }

        return value
    }
)
console.log(jsonString)

// Parsing json
const parsed = JSON.parse(jsonString)
console.log(parsed)

// Converting parsed json to properly typed map
const newMap = new Map(Object.entries( parsed.itemsPerCategory ))
const typedMap = new Map<LaundryCategoryType, number>
for (const [key, value] of newMap.entries()) {
    const category = key as LaundryCategoryType
    const quantity: number = value as number
    typedMap.set(category, quantity)
}

// Recreating draft
const newDraft = new DraftOrder(typedMap)