b method
获取 value 转 bool
Implementation
bool b(String key, {bool defaultValue = false, bool showLog = true}) {
if (!containsKey(key)) {
_log('当前map不存在 key:[$key]', showLog);
return defaultValue;
}
final value = this[key];
if (value is bool) return value;
_log('${value.runtimeType} [$key]=$value => bool:$defaultValue', showLog);
return defaultValue;
}