* This function demonstrates how to change the integration routine in one of modules.
* To make it possible, the module must inherit from MathIntegratorModule class (our doxygen documentation will tell you that).
*
* Be careful when you perform this operation.
* Some integration routines may speed up computations, but at the same time they can be not accurate enough to be applied in some kinematic ranges (e.g. in low xB).
* The infinities are also treated differently by various integration routines (or they are not treated at all).
*
* This function is the demonstration for GPD module.
* Note however that the way of changing the integration routine that is presented here is applicable to any type of PARTONS module.
* This function demonstrates how to change the integration routine in one of modules.
* To make it possible, the module must inherit from MathIntegratorModule class (our doxygen documentation will tell you that).
*
* Be careful when you perform this operation.
* Some integration routines may speed up computations, but at the same time they can be not accurate enough to be applied in some kinematic ranges (e.g. in low xB).
* The infinities are also treated differently by various integration routines (or they are not treated at all).
*
* This function is the demonstration for GPD module.
* Note however that the way of changing the integration routine that is presented here is applicable to any type of PARTONS module.