Question: ```
const member = message.mentions.members.first()
if (!message.mentions.users.size) {
  return message.channel.send('You have to mention a user to kick him!');
} else if (member === message.author) {
  return message.channel.send('You can\'t kick yourself!');
} else if (!member.kickable) {
  return message.channel.send('You cannot kick this user!');
} else {
  return member
    .kick()
    .then(() => message.message.send(`${member.user.tag} was kicked.`))
    .catch(error => message.message.send(`Sorry, an error occured.`))
}

```

I'm trying to create a code that kicks a user, but in some situations I don't want the user to be able to kick another user. One of these situations is when the user to be kicked is the same one who writes the command. The problem is that i can't do this piece of code and every time it tells me: 'You cannot kick this user!' when it should say: 'You can't kick myself'. How can i display that message when i try to kick myself?
P.S. Sorry for my english, i'm italian

Answer: 
```
  var url = Uri.parse("https://yourdomain.com/videos/$id");

```

you need to parse the url then you can add your id any extra variable .

then Call:

```
final response = await http.get(url, headers: headers);

```
Your question is insufficient as you do not provide any other information on the usage, but according to the `Only static members can be initialized` error, I will answer assuming that you are using this in a `StatefulWidget` (not `StatelessWidget` because variables are not initialized with the keyword `final`).

Your code

```dart
String email = "";
String password = "";
String url ="http://ngrok.io/authenticate/$email/$password";

```

is the same as

```dart
String email = "";
String password = "";
String url ="http://ngrok.io/authenticate/${this.email}/${this.password}";

```

Here is the problem.  

Variable `email` and `password` are members of the class, (technically of `this`). The variable `url` is also a member of the class and they are all initializers. Initializers are executed before the constructor of the class, and the constructor of the super class, and `this` is only allowed to be accessed after these constructions.
So, you can't use the value of the initializers during initialization. So, what can you do, you can use static members. 

> 
> Static members are data members (variables) or methods that belong to a static or a non static class itself, rather than to objects of the class.
> 
> 
> 

According to Google, these static members are not the ones you want in your use case, as `email` and `password` members should be different for each instance of the class. So, the best fix I can advise is to use `url` as a function or a getter and not as a member, like

```dart
String get url => "http://ngrok.io/authenticate/$email/$password";

```

I hope it helps.