Bad error message when copying a wiki to an id that already exists

    @Test
    void copyWhenWikiAlreadyExists() throws Exception
    {
        when(this.store.isWikiNameAvailable(any(String.class), any(XWikiContext.class))).thenReturn(true);
        // The wiki already exists
        when(this.wikiDescriptorManager.exists("existingid")).thenReturn(true);

        Throwable exception = assertThrows(WikiManagerException.class, () -> {
            this.wikiManager.copy("wikiid", "existingid", "newwikialias", true, true, true);
        });
        assertEquals("The wiki id [existingid] is already used or is a reserved id, and thus is not available.",
            exception.getMessage());
    }