input: from typing import List
  
  def top_10_bestselling_books(conn: sqlite3.Connection, genre: str) -> str:
      """
      Generate an HTML table displaying information about the top 10 bestselling books in a specific genre.
      The function connects to a SQLite database, queries the top 10 books by sales in the given genre, and generates an HTML table with the results.
      
      Example:
      >>> conn = sqlite3.connect('books.db')
      >>> top_10_bestselling_books(conn, 'Fantasy')
      '<table><tr><th>Title</th><th>Author</th><th>Genre</th><th>Sales</th></tr><tr><td>Example Title</td><td>Example Author</td><td>Fantasy</td><td>100000</td></tr></table>'
      """
output:     cursor = conn.cursor()
      cursor.execute("""
          SELECT title, author, genre, sales
          FROM books
          WHERE genre = ?
          ORDER BY sales DESC
          LIMIT 10
      """, (genre,))
      
      rows = cursor.fetchall()
      
      html_table = '<table><tr><th>Title</th><th>Author</th><th>Genre</th><th>Sales</th></tr>'
      for row in rows:
          title, author, genre, sales = row
          html_table += f'<tr><td>{title}</td><td>{author}</td><td>{genre}</td><td>{sales}</td></tr>'
      html_table += '</table>'
      
      return html_table