<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def url(self, url):
 """ Sets the url of this FileSourceCreateRequest. Source URL of file. Must be an http, https. :param url: The url of this FileSourceCreateRequest. :type: str """

        if url is None:
            raise ValueError("Invalid value for `url`, must not be `None`")
        if url is not None and len(url) > 4096:
            raise ValueError("Invalid value for `url`, length must be less than or equal to `4096`")
        if url is not None and len(url) < 1:
            raise ValueError("Invalid value for `url`, length must be greater than or equal to `1`")
        if url is not None and not re.search('^https?:.*', url):
            raise ValueError("Invalid value for `url`, must be a follow pattern or equal to `/^https?:.*/`")

        self._url = url