input: Write a python function to count the occurrence of a keyword on a webpage.
  ```python
  import requests
  from bs4 import BeautifulSoup
  
  def count_keyword_occurrences(url, keyword):
      r = requests.get(url)
      html_doc = r.text
      soup = BeautifulSoup(html_doc, 'html.parser')
      keyword_count = soup.find_all(string=keyword).__len__()
      return keyword_count
  
  assert count_keyword_occurrences('http://example.com', 'example') == 2  # Adjust according to actual occurrences on the page
  assert count_keyword_occurrences('http://example.com', 'html') == 0  # Adjust according to actual occurrences on the page
  assert count_keyword_occurrences('http://example.com', 'Example') == 1  # Adjust according to actual occurrences on the page
output: import requests
  from bs4 import BeautifulSoup
  
  def count_keyword_occurrences(url, keyword):
      r = requests.get(url)
      html_doc = r.text
      soup = BeautifulSoup(html_doc, 'html.parser')
      keyword_count = soup.find_all(string=lambda text: text and keyword in text).__len__()
      return keyword_count
  
  assert count_keyword_occurrences('http://example.com', 'example') == 2  # Adjust according to actual occurrences on the page
  assert count_keyword_occurrences('http://example.com', 'html') == 0  # Adjust according to actual occurrences on the page
  assert count_keyword_occurrences('http://example.com', 'Example') == 1  # Adjust according to actual occurrences on the page