input: from typing import Set, List
  
  import requests
  from bs4 import BeautifulSoup
  import re
  
  def crawl(url: str) -> None:
      """
      This function implements a simple web crawler that starts from a given URL and explores other links found on the page. It scrapes the content of each visited page.
      >>> crawl('http://example.com')
      
      """
      visited: Set[str] = set()
      queue: List[str] = [url]
      
      while queue:
          curr: str = queue.pop(0)
          visited.add(curr)
          response: requests.Response = requests.get(curr)
          
          if response.ok:
              soup: BeautifulSoup = BeautifulSoup(response.text, 'html.parser')
              # scrape the page here 
              
              # find all the links
              links: List[BeautifulSoup] = soup.find_all('a', href=re.compile('^http'))
              
              for link in links:
                  if link['href'] not in visited:
                      queue.append(link['href'])
output:     
              # scrape the page here 
              print(f"Scraping content from {curr}")
              content: str = soup.get_text()
              print(content)
              
              # find all the links
              links: List[BeautifulSoup] = soup.find_all('a', href=re.compile('^http'))
              
              for link in links:
                  if link['href'] not in visited:
                      queue.append(link['href'])
  