code: function strictEqual(actual, expected, message) {
      if (actual === expected) {
        this.pass(message);
      }
      else {
        this.fail({
          actual: actual,
          expected: expected,
          message: message,
          operator: "==="
        });
      }
    }
docs: The strict equality assertion tests strict equality, as determined by
  `===`.
  @example
  assert.strictEqual(null, null, "`null` is `null`")