1 function isSymbol(value)
3 return typeof value === 'symbol';
10 [ "Cappuccino", false ],
11 [ Symbol('Cocoa'), true ],
17 for (var i = 0; i < 1e4; ++i) {
18 for (let pair of list) {
19 if (isSymbol(pair[0]) != pair[1])
20 throw new Error(`bad value:${String(pair[0])}, ${pair[1]}`);