def remove(self, elem):
        """Remove a requirement.

        :param elem: a string or :class:`Requirement` instance.
        """
        if isinstance(elem, text_type):
            for requirement in self:
                if requirement.package == elem:
                    return super(Requirements, self).remove(requirement)
        return super(Requirements, self).remove(elem)
def __init__(self, schema_file: str):
        self._schema = artifact_utils.read_schema_file(schema_file)

        self._type_name, self._metric_fields = artifact_utils.parse_schema(
            self._schema)

        self._values = {}