.to.be.true; in postman

var schema = {
 "items": {
 "type": "boolean"
 }
};
var data1 = [true, false];
var data2 = [true, 123];

pm.test('Schema is valid', function() {
  pm.expect(tv4.validate(data1, schema)).to.be.true;
  pm.expect(tv4.validate(data2, schema)).to.be.true;
});