I want to create a custom exception that builder classes can throw if the build method is called before all the required components are configured.
For example in this class:
class AuthenticationTokenBuilder
{
     private readonly ?string $username;
     private readonly ?string $token;

     public function setUsername(string $username): AuthenticationTokenBuilder {
         $this->username = $username;
         return $this;
     }

     public function setToken(string $token): AuthenticationTokenBuilder {
         $this->token = $token;
         return $this;
     }

     public function build(): string {
         return $this->username . '_' . $this->token;
     }
}

I will throw this exception if the build method is called before the username or token values are set.
So, please suggest me the most concise and best name for such an exception. Provide your reponse without using the word authenticationtokenbuilder.
user