src/vs/editor/common/languages/supports/tokenization.ts/ExternalThemeTrieElement/constructor
class ExternalThemeTrieElement:	constructor(
		mainRule: ThemeTrieElementRule,
		children: Map<string, ExternalThemeTrieElement> | { [key: string]: ExternalThemeTrieElement } = new Map<string, ExternalThemeTrieElement>()
	) {
		this.mainRule = mainRule;
		if (children instanceof Map) {
			this.children = children;
		} else {
			this.children = new Map<string, ExternalThemeTrieElement>();
			for (const key in children) {
				this.children.set(key, children[key]);
			}
		}
	}