def __init__(self, groups=None):
        super(GroupedRequirements, self).__init__(NamedRequirements)
        self.groups = groups or self.default_groups
        self.filename = None
        self.create_default_groups()
def get_schema(self):
        """Returns the set YAML schema for the metric class.

        Returns:
          YAML schema of the metrics type.
        """
        return self._schema