src/vs/workbench/services/themes/common/colorThemeData.ts/ColorThemeData/readSemanticTokenRules
class ColorThemeData:	private readSemanticTokenRules(tokenStylingRuleSection: ISemanticTokenRules) {
		for (let key in tokenStylingRuleSection) {
			if (key[0] !== '[') { // still do this test until experimental settings are gone
				try {
					const rule = readSemanticTokenRule(key, tokenStylingRuleSection[key]);
					if (rule) {
						this.customSemanticTokenRules.push(rule);
					}
				} catch (e) {
					// invalid selector, ignore
				}
			}
		}
	}