Implement placeholder mechanism for the header of the grid ---------------------------------------------------------- Key: DROOLS-3315 URL: https://issues.redhat.com/browse/DROOLS-3315 Project: Drools Issue Type: Enhancement Components: Scenario Simulation and Testing Reporter: Daniele Zonca Assignee: Gabriele Cardosi Priority: Minor Labels: ScenarioSimulation, drools-tools Implement directly in core-grids an extension of placeholder mechanism to cover also the header