Bug 181121 Model should provide utility method for cube to get correspond dimension key.
In model cube handle, the relation of cube data set and dimension data sets are managed by a series of dimension condition handles.We need model to add utility method so that we can easily get corresponding dimension data set column names according to given cube dimension keys.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/parser/StructureState.java
element, propDefn.getName( ) );
			( (Structure) struct ).setContext( structContext );
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.util.AbstractParseState#startElement(java.lang.String)
	 */
	public AbstractParseState startElement( String tagName )
	{
		if ( tagName.equalsIgnoreCase( DesignSchemaConstants.PROPERTY_TAG ) )
			return new PropertyState( handler, element, propDefn, struct );
		if ( tagName
				.equalsIgnoreCase( DesignSchemaConstants.ENCRYPTED_PROPERTY_TAG ) )
			return new EncryptedPropertyState( handler, element, propDefn,
					struct );
		if ( tagName.equalsIgnoreCase( DesignSchemaConstants.EXPRESSION_TAG ) )
			return new ExpressionState( handler, element, propDefn, struct );
		if ( tagName.equalsIgnoreCase( DesignSchemaConstants.XML_PROPERTY_TAG ) )
			return new XmlPropertyState( handler, element, propDefn, struct );
		if ( tagName.equalsIgnoreCase( DesignSchemaConstants.LIST_PROPERTY_TAG ) )
			return new ListPropertyState( handler, element, propDefn, struct );
		if ( tagName.equalsIgnoreCase( DesignSchemaConstants.TEXT_PROPERTY_TAG ) )
			return new TextPropertyState( handler, element, struct );
		if ( tagName.equalsIgnoreCase( DesignSchemaConstants.HTML_PROPERTY_TAG ) )
			return new TextPropertyState( handler, element, struct );
		if ( tagName.equalsIgnoreCase( DesignSchemaConstants.STRUCTURE_TAG ) )
			return new StructureState( handler, element, propDefn, struct );
		if ( tagName