Assert.isNotNull( columnName);
Assert.isNotNull( columnName ); if ( StringUtil.isBlank( columnName ) ) { return null; }
	public static String getColumnExpression(String columnName)	{		Assert.isNotNull( columnName);		return IReportElementConstants.DATA_COLUMN_PREFIX			+ "[\"" + DEUtil.escape( columnName ) + "\"]";//$NON-NLS-1$ //$NON-NLS-2$	}