Add check if a collab is actually just a rant

Author: LucaScorpion

src/main/java/com/scorpiac/javarant/Collab.java

@@ -3,6 +3,7 @@
 import com.google.gson.JsonArray;
 import com.google.gson.JsonObject;
 import com.scorpiac.javarant.exceptions.NoSuchRantException;
+import com.scorpiac.javarant.exceptions.NotACollabException;
 
 public class Collab extends Rant {
     private String projectType;
@@ -42,6 +43,10 @@ public static Collab byId(int id) {
     }
 
     static Collab fromJson(JsonObject json) {
+        // Check if the rant is also a collab.
+        if (json.has("id") && !json.has("c_type_long"))
+            throw new NotACollabException(json.get("id").getAsInt());
+
         return new Collab(
                 json.get("id").getAsInt(),
                 User.fromJson(json),

src/main/java/com/scorpiac/javarant/exceptions/NotACollabException.java

@@ -0,0 +1,12 @@
+package com.scorpiac.javarant.exceptions;
+
+public class NotACollabException extends RuntimeException {
+    /**
+     * Create a new exception for a rant that is not a collab.
+     *
+     * @param id The id of the rant.
+     */
+    public NotACollabException(int id) {
+        super("Rant with id " + id + " is not a collab.");
+    }
+}