Bug 206850 [Regression] Error pops up when select value for a map or highlight rule to group header row [0302]
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/elements/structures/StyleRule.java
{
	/**
	 * Name of the comparison operator member.
	 */
	public static final String OPERATOR_MEMBER = "operator"; 
	/**
	 * Name of the property that gives the expression for the first operator
	 * operand.
	 */