isDate (value) {
    return value && typeof value === 'object' && toStr(value) === DATE_TAG
  }
Return whether the provided value is a date.

@example
import { utils } from 'js-data';
const a = new Date();
const b = { foo: "bar" };
console.log(utils.isDate(a)); // true
console.log(utils.isDate(b)); // false

@method utils.isDate
@param {*} value The value to test.
@returns {Date} Whether the provided value is a date.
@since 3.0.0