@staticmethod
def decompose_quantity(quantity_clause):
    """Decompose a quantity into operators and quantities.

        Decompose the *quantity_clause* string into operator and base
        quantity constituents. Because multiple operators can act on a
        quantity, the operators are given as a tuple regardless of the
        number of operators actually present. Returns the parts of the
        quantity as a tuple of (operators, base_quantity)

        Parameters
        ----------
        quantity_clause : str
            A CSDMS Standard Name quantity.

        Returns
        -------
        tuple of str
            The parts of the quantity as ``(operators, quantity)``.
        """
    quantity_parts = quantity_clause.split('_of_')
    quantity = quantity_parts[-1]
    operators = tuple(quantity_parts[:-1])
    return operators, quantity
