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 __getattr__(self, name: str) -> Any:
        """Custom __getattr__ to allow access to metrics schema fields."""

        if name not in self._metric_fields:
            raise AttributeError('No field: {} in metrics.'.format(name))

        return self._values[name]