Method to get the appropriate normalization range dictionary
        given a key and element.

def get_ranges(self, element, key):
        """
        Method to get the appropriate normalization range dictionary
        given a key and element.
        """
        keys = self.p['keys']
        ranges = self.p['ranges']

        if ranges == {}:
            return {d.name: element.range(d.name, self.data_range)
                    for d in element.dimensions()}
        if keys is None:
            specs = ranges
        elif keys and not isinstance(ranges, list):
            raise ValueError("Key list specified but ranges parameter"
                             " not specified as a list.")
        elif len(keys) == len(ranges):
            # Unpack any 1-tuple keys
            try:
                index = keys.index(key)
                specs = ranges[index]
            except:
                raise KeyError("Could not match element key to defined keys")
        else:
            raise ValueError("Key list length must match length of supplied ranges")

        return match_spec(element, specs)