Bug 121687 Exception throws when export data in table which inside a grid cell.
Description: Exception throws when export data in table which inside a grid cell. Steps to reproduce: 1. insert a grid. 2. insert one table to one grid cell. 3. insert another table to the other grid cell. 4. export data in two tables. Expected result: Data are exported. Actual result: Exception in: ReportEngineService.getMetaData( )
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/ir/Report.java
{
		assert allParameters != null;
		assert params != null;
		IParameterDefnBase param;
		for ( int n = 0; n < params.size( ); n++ )
		{
			param = (IParameterDefnBase) params.get( n );
			if ( param.getParameterType( ) == IParameterDefnBase.PARAMETER_GROUP )
			{
				flattenParameter( ( (IParameterGroupDefn) param ).getContents( ) );
			}
			else
			{
				allParameters.add( param );
			}
		}
	}
	/**
	 * Gets the parameter list of the report.
	 * 
	 * @param includeParameterGroups
	 *            A <code>boolean</code> value specifies whether to include
	 *            parameter groups or not.
	 * @return The collection of top-level report parameters and parameter
	 *         groups if <code>includeParameterGroups</code> is set to
	 *         <code>true</code>; otherwise, returns all the report
	 *         parameters.
	 */
	public ArrayList getParameters( boolean includeParameterGroups )
	{