         
         func test(writer: DatabaseWriter) throws {
             try XCTAssertEqual(writer.read(Player.fetchCount), 0)
-            let single = writer.rx.write(updates: { db in
+            let completable = writer.rx.write(updates: { db in
                 try Player(id: 1, name: "Arthur", score: 1000).insert(db)
             })
-            _ = try single.toBlocking(timeout: 1).last()
+            _ = try completable.toBlocking(timeout: 1).last()
             try XCTAssertEqual(writer.read(Player.fetchCount), 1)
         }
         

    
    // MARK: -
    
    func testWriteAndReturnObservableError() throws {
        func test(writer: DatabaseWriter) throws {
            let single = writer.rx.writeAndReturn(updates: { db in

    
    func testWriteObservableError() throws {
        func test(writer: DatabaseWriter) throws {
            let completable = writer.rx.write(updates: { db in
                try db.execute(sql: "THIS IS NOT SQL")
            })
            do {
                _ = try completable.toBlocking(timeout: 1).last()
                XCTFail("Expected error")
            } catch let error as DatabaseError {
                XCTAssertEqual(error.resultCode, .SQLITE_ERROR)
