input: Write a python function to extract the programming language names from the given HTML string.
  assert extract_languages(html_string) == ["JavaScript", "Python", "C", "C++", "Java"]
  html_string = """
  <html>
  <head>
  <title>Programming Languages</title>
  </head>
  <body>
  <h1>Programming Languages</h1>
  <ul>
  <li><b>JavaScript</b> – Object-oriented, event-driven, and functional programming language</li>
  <li><b>Python</b> – Object-oriented, interpreted, high-level programming language</li>
  <li><b>C</b> – High-level, structured, multiparadigm, compiled programming language</li>
  <li><b>C++</b> – Object-oriented, compiled, generic programming language</li>
  <li><b>Java</b> – Object-oriented, portable, compiled programming language</li>
  </ul>
  </body>
  </html>
  """
output: def extract_languages(html_string):
      from bs4 import BeautifulSoup
  
      soup = BeautifulSoup(html_string, 'html.parser')
      languages = [li.b.get_text() for li in soup.find_all('li')]
      return languages