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
* 
	 * @param cubeKey
	 *            the cube key to set
	 */
	public void setCubeKey( String cubeKey )
	{
		setPropertySilently( DimensionJoinCondition.CUBE_KEY_MEMBER, cubeKey );
	}
	/**
	 * Gets the hierarchy key in this dimension join condition.
	 * 
	 * @return the hierarchy key in this dimension join condition
	 */
	public String getHierarchyKey( )
	{
		return getStringProperty( DimensionJoinCondition.HIERARCHY_KEY_MEMBER );
	}
	/**
	 * Sets the hierarchy key in this dimension join condition.
	 * 
	 * @param hierarchyKey
	 *            the hierarchy key to set
	 */
	public void setHierarchyKey( String hierarchyKey )
	{
		setPropertySilently( DimensionJoinCondition.HIERARCHY_KEY_MEMBER,
				hierarchyKey );
	}
}