```java.net.URL``` is not a POJO recording a URL as a structured string, it does some "intelligent" things. I should habe never used it as a hash table key.

```$ jshell```
```| Welcome to JShell -- Version 17.0.3.1```
```| For an introduction type: /help intro```
``` ```
```jshell> var u1 = new URL("https://fr.wikipedia.org/wiki/Sp%C3%A9cial:Contributions/Kolmigabrouil")```
```u1 ==> https://fr.wikipedia.org/wiki/Sp%C3%A9cial:Contributions/Kolmigabrouil```
``` ```
```jshell> var u2 = new URL("https://en.wikipedia.org/wiki/Sp%C3%A9cial:Contributions/Kolmigabrouil")```
```u2 ==> https://en.wikipedia.org/wiki/Sp%C3%A9cial:Contributions/Kolmigabrouil```
``` ```
```jshell> u1.equals(u2)```
```$3 ==> true```