Bug 132786 Value2 should be cleaned after convert operator from between to equal in highlight rule.
Description: Value2 should be cleaned after convert operator from between to equal in highlight rule. Steps to reproduce: 1. Insert a data. 2. Set highlight rule in Property Editor. 2 between 1 and 3, color blue. 3. Save the report 4. Modify highlight rule, change to 1 equal 1, color blue. 5. Save the report, see generated xml source. Expected result: In xml source, value2 should be cleaned in highlight expression. Actual result: In xml source, value1 is 1 and value2 is 3.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/HighlightRuleHandle.java
*/
	public String getDateTimeFormat( )
	{
		Object value = getProperty( HighlightRule.DATE_TIME_FORMAT_MEMBER );
		if ( value == null )
			return null;
		assert value instanceof DateTimeFormatValue;
		return ( (DateTimeFormatValue) value ).getPattern( );
	}
	/**
	 * Returns the category of the date-time-format for a highlight rule.
	 * 
	 * @return the category of the date-time-format
	 */
	public String getDateTimeFormatCategory( )
	{
		Object value = getProperty( HighlightRule.DATE_TIME_FORMAT_MEMBER );
		if ( value == null )
			return null;
		assert value instanceof DateTimeFormatValue;
		return ( (DateTimeFormatValue) value ).getCategory( );
	}
	/**
	 * Sets the pattern of a date time format for a highlight rule.
	 * 
	 * @param pattern
	 *            the pattern of a date time format
	 */
	public void setDateTimeFormat( String pattern )
	{