code: function Specification (description, msg, f, options) {
    this.id = ++id;
    // Static fields:
    this.description = description;
    description.log_("Specification: " + msg);
    description.specifications.push(this);
    this.message = msg;
    this.behavior = f;
    this.stopOnFailure = false;
    this.expectationIntended = undefined;
    this.verbose = description.verbose;
    Object.assign(this, options || {});
    // Internal (dynamic) fields:
    this.expectations = [];
    this.result = undefined;
    this.raisedException = false;
    this.exception = null;
    this.index = 0;
    this.expectationAttempted = 0;
    this.expectationSuccessful = 0;
    this.pass = false;
  }
docs: *********** Specification *************