t.Errorf("%d. WriteStringError = %d, %v, want 0, unwritable", i, n, err)
		}
	}
}

// TestGenericTrieBuilding verifies the structure of the generated trie. There
// is one node per line, and the key ending with the current line is in the
// trie if it ends with a "+".
func TestGenericTrieBuilding(t *testing.T) {
	testCases := []struct{ in, out string }{
		{"abc;abdef;abdefgh;xx;xy;z", `-
			a-
			.b-