Use Collection#toArray(T[]) instead.

Like the toArray() method, this method acts as bridge between array-based and collection-based APIs. Further, this method allows precise control over the runtime type of the output array, and may, under certain circumstances, be used to save allocation costs.

src/main/java/net/dv8tion/jda/core/Permission.java

@@ -171,6 +171,6 @@ public static long getRaw(Permission... permissions)
 
     public static long getRaw(Collection<Permission> permissions)
     {
-        return getRaw(permissions.stream().toArray(Permission[]::new));
+        return getRaw(permissions.toArray(new Permission[permissions.size()]));
     }
 }