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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def from_url(cls, url: URL, *, encoding: str='latin1') -> Optional['BasicAuth']: """Create BasicAuth from url."""

        if not isinstance(url, URL):
            raise TypeError("url should be yarl.URL instance")
        if url.user is None:
            return None
        return cls(url.user, url.password or '', encoding=encoding)