Bug 183579 Model need hold on DimensionConditionHandle and DimensionJoinConditionHandle signleton or overwrites the equals and hashcode method
The Dataset Joint Editor need join two Editparts which have the same model. But the DimensionConditionHandle and the DimensionJoinConditionHandle are create a new instance erery time when I get them. So model need hold on them signleton or overwrites the equals and hashcode method.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/DimensionJoinConditionHandle.java
{
	/**
	 * Constructs a dimension join condition handle with the given
	 * <code>SimpleValueHandle</code> and the index of the dimension join
	 * condition in the dimension condition.
	 * 
	 * @param valueHandle
	 *            handle to a list property or member
	 * @param index
	 *            index of the structure within the list
	 */
	public DimensionJoinConditionHandle( SimpleValueHandle valueHandle,
			int index )
	{
		super( valueHandle, index );
	}
	/**
	 * Gets the cube key in this dimension join condition.
	 * 
	 * @return the cube key in this dimension join condition
	 */
	public String getCubeKey( )
	{
		return getStringProperty( DimensionJoinCondition.CUBE_KEY_MEMBER );
	}
	/**
	 * Sets the cube key in this dimension join condition.