in src/langs/common/items.js [438:450]
constructor(key, value) {
super();
const typeMap = ['number', 'string', 'boolean'];
let type = typeof value;
if (value === null || value === 'null') {
type = 'null';
} else if (typeMap.indexOf(type) === -1) {
throw new Error(`Not suppoted type : ${type} [${typeMap.toString()}]`);
}
this.key = key;
this.value = value;
this.type = type;
}