static isArray(arr) {
        if (Object.prototype.toString.call([]) === '[object Array]') { // Make sure an array has a class attribute of [object Array]
            // Test passed, now check if is an Array
            return Array.isArray(arr) || (typeof arr === 'object' && Object.prototype.toString.call(arr) === '[object Array]');
        }
        else {
            throw new Error('toString message changed for Object Array'); // Verify that the string returned by `toString` does not change in the future (cf. http://stackoverflow.com/a/8365215)
        }
    }
Return `true` if the parameter is an Array
//TODO Replace this by the default `Array.isArray()` function?

@param {*} arr
@throws Error
@returns {*|boolean}