MoveIt: how to use class MoveGroup::MoveGroupImpl?

Hi everyone, I would like to use the function `void setReplanningDelay(double delay)` belonging to class MoveGroup::MoveGroupImpl, because I need to decrease the 2 seconds default value of `replan_delay_`. How could I implement that function? An example of code would be really helpful. I think another option is to manually decrease that value, but this would require installing Moveit in the workspace I guess, but I would leave this option as the last resort. ROS version: Kinetic Ubuntu: 16.04