code: public function setGender($gender)
      {
          $allowed_values = array('Male', 'Female', 'Other');
          if (!is_null($gender) && (!in_array($gender, $allowed_values))) {
              throw new \InvalidArgumentException("Invalid value for 'gender', must be one of 'Male', 'Female', 'Other'");
          }
          $this->container['gender'] = $gender;
  
          return $this;
      }
docs: Sets gender
  @param string $gender The shopper's gender
  @return $this