input: from typing import List, Tuple
  
  def generate_html_table(table_name: str, columns: List[str], genre: str) -> str:
      """Generates an HTML table displaying information about the top 10 bestselling 
      books in a specific genre from a SQLite database. The table will include columns
      for book title, author, genre, and sales.
  
      >>> generate_html_table('Books', ['id', 'title', 'author', 'genre', 'sales'], 'Fantasy')
      '<table><tr><th>Title</th><th>Author</th><th>Genre</th><th>Sales</th></tr><tr><td>[TITLE]</td><td>[AUTHOR]</td><td>[GENRE]</td><td>[SALES]</td></tr><tr><td>[TITLE]</td><td>[AUTHOR]</td><td>[GENRE]</td><td>[SALES]</td></tr></table>'
      """
output:     html = f'<table><tr>'
      for col in columns:
          html += f'<th>{col.capitalize()}</th>'
      html += '</tr>'
      
      for _ in range(10):
          html += '<tr>'
          for col in columns:
              html += f'<td>[{col.upper()}]</td>'
          html += '</tr>'
      
      html += '</table>'
      return html