function createBook(data) {
  return db.insert("books", data);
}

function createBook(data) {
  if (!data) {
    throw new Error("expected data to create a book");
  }
  
  return db.insert("books", data);
}

function createBook(data) {
  if (!data) {
    throw new Error("expected data to create a book");
  }
  
   if (Array.isArray(data)) {
    throw new Error("expected data to be an Object");
  }
  
  return db.insert("books", data);
}

function createBook(data) {
  if (!data) {
    throw new Error("expected data to create a book");
  }
  
   if (Array.isArray(data)) {
    throw new Error("expected data to be an Object");
  }
  
  if (!data.title) {
    throw new Error("expected data.title");
  }
 
  return db.insert("books", data);
}