assertTrue(ex.getMessage().contains("Not connected"));
    }

    @Test
    @DisplayName("getTreeId delegates")
    void getTreeIdDelegates() {
        // Ensures tree id is forwarded from connection
        when(treeConnection.getTreeId()).thenReturn(42L);
        assertEquals(42L, handle.getTreeId());
        verify(treeConnection).getTreeId();
    }