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/parser/EngineIRVisitor.java
.getExpression( ) ) );
			}
			drillThrough.setParameters( params );
			
			
			
			
			
			
			
			
			
			
			
		}
		else
		{
			assert ( false );
		}
		return action;
	}
	/**
	 * create a highlight rule from a structure handle.
	 * 
	 * @param ruleHandle
	 *            rule in the MODEL.
	 * @return rule design, null if exist any error.
	 */
	protected HighlightRuleDesign createHighlightRule(
			StructureHandle ruleHandle, String defaultStr )