Walk through the nested dict structure and executes
        horizontal_operation(name, callable) resp.
        vertical_operation(name, callable) if defined.

def buildHirarchy(self, horizontal_operation=None,
                      vertical_operation=None):
        """Walk through the nested dict structure and executes
        horizontal_operation(name, callable) resp.
        vertical_operation(name, callable) if defined.
        """
        def buildRecursive(pkey, pval):
            if self.isNestedDict(pval):
                if vertical_operation:
                    vertical_operation(pkey, pval)
                for key, val in list(pval.items()):
                    # if not isinstance(val, NestedOrderedDict):
                    buildRecursive(key, val)
            else:
                if horizontal_operation:
                    horizontal_operation(pkey, pval)
        buildRecursive(self._package.__name__, self)