code: function Email(obj){
      this._id = obj && obj.id;
      this._tag = obj && obj.tag;
      this._email = obj && obj.email;
      this._emailStatus = obj && obj.emailStatus;
  
      if (this._tag == undefined || this._tag == null){
          throw 'Tag is a required field'
      }
      if (this._email == undefined || this._email == null){
          throw 'Email is a required field'
      }
  }
docs: Contact Email information
  @typedef {Object} Contact.Email
  @property {string} tag - a context tag
  @property {string} email - The email address to add
  @property {string} contactSubscriptionStatus - The subscription status of the current contact ['optIn' or 'optInOut' or 'notSet']
  @property {string} siteOwnerSubscriptionStatus - The subscription status of the site owner in relation to this contact ['optIn' or 'optInOut' or 'notSet']