input: 
  from typing import List, Tuple
  import sqlite3
  
  def generate_book_table(genre: str) -> str:
      """ Generate an HTML table displaying the top 10 bestselling books in a specific genre.
      >>> generate_book_table('Fantasy')
      '<table><tr><th>Title</th><th>Author</th><th>Genre</th><th>Sales</th></tr><tr><td>Book1</td><td>Author1</td><td>Fantasy</td><td>1000</td></tr><tr><td>Book2</td><td>Author2</td><td>Fantasy</td><td>900</td></tr></table>'
      >>> generate_book_table('Mystery')
      '<table><tr><th>Title</th><th>Author</th><th>Genre</th><th>Sales</th></tr><tr><td>BookA</td><td>AuthorA</td><td>Mystery</td><td>1200</td></tr><tr><td>BookB</td><td>AuthorB</td><td>Mystery</td><td>850</td></tr></table>'
      """
      conn = sqlite3.connect('books.db')
      c = conn.cursor()
      c.execute('''SELECT title, author, genre, sales
                  FROM Books
                  WHERE genre=?
                  ORDER BY sales DESC
                  LIMIT 10''', (genre,))
      results = c.fetchall()
      html = '<table>'
      html += '<tr><th>Title</th><th>Author</th><th>Genre</th><th>Sales</th></tr>'
      for result in results:
          title, author, genre, sales = result
          html += f'<tr><td>{title}</td><td>{author}</td><td>{genre}</td><td>{sales}</td></tr>'
      html += '</table>'
      conn.close()
      return html
  
output:     conn = sqlite3.connect('books.db')
      c = conn.cursor()
      c.execute('''SELECT title, author, genre, sales
                  FROM Books
                  WHERE genre=?
                  ORDER BY sales DESC
                  LIMIT 10''', (genre,))
      results = c.fetchall()
      html = '<table>'
      html += '<tr><th>Title</th><th>Author</th><th>Genre</th><th>Sales</th></tr>'
      for result in results:
          title, author, genre, sales = result
          html += f'<tr><td>{title}</td><td>{author}</td><td>{genre}</td><td>{sales}</td></tr>'
      html += '</table>'
      conn.close()
      return html