Bug 161174 Expect to set/get interval range with a 'String' param in GroupHandle.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/GroupHandle.java
* 
	 * @return a slot handle to the footer
	 */
	public SlotHandle getFooter( )
	{
		return getSlot( GroupElement.FOOTER_SLOT );
	}
	/**
	 * Gets the expression that defines the group. This is normally simply a
	 * reference to a data set column.
	 * 
	 * @return the expression as a string
	 * 
	 * @see #setKeyExpr(String)
	 */
	public String getKeyExpr( )
	{
		return getStringProperty( GroupElement.KEY_EXPR_PROP );
	}
	/**
	 * Gets the name of the group.
	 * 
	 * @return the name of the group
	 */
	public String getName( )
	{
		return getStringProperty( GroupElement.GROUP_NAME_PROP );
	}
	/**
	 * Sets the group name.