Bug 168026 Still use the existing data binding even though the aggregate is different
I had a table in which a data binding which aggregates on a group. When I insert a new data item in the report, although the expressions are same, it aggregates on All, then it refered to the existing data binding. The expected behavior would be a new data binding is created with different aggregates.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ScalarParameterHandle.java
* Tests whether hides the user's entry by displaying asterisks. Often used
	 * for passwords.
	 * 
	 * @return <code>true</code> if hides the user's entry by asterisks,
	 *         <code>false</code> if shows characters as usual.
	 */
	public boolean isConcealValue( )
	{
		return getBooleanProperty( CONCEAL_VALUE_PROP );
	}
	/**
	 * Sets the attribute that's hides the user's entry by displaying asterisks.
	 * Often used for passwords.
	 * 
	 * @param concealValue
	 *            <code>true</code> if hides the user's entry by asterisks,
	 *            <code>false</code> if shows characters as usual.
	 * @throws SemanticException
	 *             if the property is locked.
	 */
	public void setConcealValue( boolean concealValue )
			throws SemanticException
	{
		setProperty( CONCEAL_VALUE_PROP, Boolean.valueOf( concealValue ) );
	}
	/**
	 * Tests whether the value of the parameter can be <code>null</code>.
	 * 
	 * @return <code>true</code> if the value can be <code>null</code>,
	 *         <code>false</code> if the value can not be <code>null</code>.