Search a collection for the distinct key values provided.

        Args:
            collection: The db collection. See main class documentation.
            key: The name of the key to find distinct values. For example with
                 the indicators collection, the key could be "type".
        Returns:
            List of distinct values.

def find_distinct(self, collection, key):
        """
        Search a collection for the distinct key values provided.

        Args:
            collection: The db collection. See main class documentation.
            key: The name of the key to find distinct values. For example with
                 the indicators collection, the key could be "type".
        Returns:
            List of distinct values.
        """
        obj = getattr(self.db, collection)
        result = obj.distinct(key)
        return result