def coerce(cls, string):
        """Create a :class:`Requirement` object from a given package spec."""
        match = re.match(cls.spec_regex, string)
        if not match:
            raise InvalidRequirementSpecError("could not parse requirement")
        package = match.group(1)
        if all(match.group(2, 3)):
            version = "".join(match.group(2, 3))
        else:
            version = None
        return cls(package, version)
def describe(self) -> None:
        """Logs a profile report after the conclusion of run."""
        # there are pickling issues with open file handles in Python 3.6
        # so to avoid them, we open and close the files within this function
        # by calling `_prepare_streams` and `teardown`
        self._prepare_streams()
        summary = self.summary()
        if summary:
            self._write_stream(summary)
        if self._output_file is not None:
            self._output_file.flush()
        self.teardown(stage=self._stage)