const { message }

JavaScript
const { bar } = foo; // where foo = { bar:5, baz:2, bat: 10 };
/* This creates a constant with the name 'bar', which has a value of 5 */
const { message } = new assert.AssertionError({
  actual: 1,
  expected: 2,
  operator: 'strictEqual'
});
Source

Also in JavaScript: