function AssertionError (options) {
      options = options || {};
      this.message = options.message;
      this.actual = options.actual;
      this.expected = options.expected;
      this.operator = options.operator;
      this.showDiff = options.showDiff;

      if (options.stackStartFunction && Error.captureStackTrace) {
        var stackStartFunction = options.stackStartFunction;
        Error.captureStackTrace(this, stackStartFunction);
      }
    }
# AssertionError (constructor)

Create a new assertion error based on the Javascript
`Error` prototype.

**Options**
- message
- actual
- expected
- operator
- startStackFunction

@param {Object} options
@api public