def prepare(link:str):
	"""A function to check if the link is complete (it includes the protocol) 
	and that it can be used by the library (it should not end with a slash)


	Args:
		**link (str)**: The link to check/prepare

	Raises:
		**Exception**: Thrown if the protocol is not present in the URL 

	Returns:
		**str**: prepared link
	"""
	if(link.endswith("/")):
		link = link[:-1]
	if("http" not in link):
		raise Exception(f"{link} is not a valid URL!")
	return link