Defines a simple OLAP Result and Metadata.

## Overview

The OlapModel provides access to the {@link com.tonbeller.jpivot.olap.model.Result} of a query. It does not specify the query itself (e.g. what data will be displayed).

The interfaces in this package define a minimal OLAP result. The definitions are independent of an implementation like Mondrian or JOLAP. It only defines what is necessary to display the result to the user.

## OLAP Result

To support "ragged hierarchies" or "parent-child hierarchies" no assuptions are made regarding the number, ordering or hierarchy of Levels instances. See Microsofts definition of Parent-Child Hierarchy

## Expressions