irBeams inside IRSensor

edit

I'm working with gazebo simulator, in the IRSensor.hh file (in gazebo/build/gazebo/server/sensors/ir/IRSensor.hh) is declared

private std::vector<RaySensor*> irBeams;

And then, in the IRSensor.cc file (in gazebo/build/gazebo/server/sensors/ir/IRSensor.cc) is used this structure in order to use the parameters of the sensor like

    unsigned int IRSensor::GetIRCount() const
    {
      return this->irBeams.size();
    }

But this structure is nowhere defined or filled inside this file. How is this possible? Where is it?

I ask because i try to use this function (GetIRCount) after configuring a IRSensor through a XML file and it always return 0 because it is empty and i really don't why.

https://kforge.ros.org/gazebo/trac/browser/server/sensors/ir/IRSensor.cc