input: Write a python function to extract the text content of the <h1> and <footer> elements from an HTML string.
  assert extract_text_from_html("<html><head><title>Sample Page</title></head><body><h1>Sample Page</h1><p>This page has a header, a body, and a footer.</p><footer><p>This is the footer.</p></footer></body></html>") == ("Sample Page", "This is the footer.")
  assert extract_text_from_html("<html><head><title>Test Page</title></head><body><h1>Test Header</h1><p>Content.</p><footer><p>Footer content.</p></footer></body></html>") == ("Test Header", "Footer content.")
  assert extract_text_from_html("<html><body><h1>Header</h1><footer><p>Footer</p></footer></body></html>") == ("Header", "Footer")
output: def extract_text_from_html(html):
      from bs4 import BeautifulSoup
      
      soup = BeautifulSoup(html, 'html.parser')
      
      h1_text = soup.find('h1').get_text() if soup.find('h1') else ''
      footer_text = soup.find('footer').get_text() if soup.find('footer') else ''
      
      return h1_text, footer_text.strip()