text: #ifndef _BOUNDARY_H_
  #define _BOUNDARY_H_
  
  #define FLUID 0
  #define NO_SLIP 1
  #define MOVING_WALL 2
  
  /** handles the boundaries in our simulation setup */
  void treatBoundary(double *collideField, int* flagField, const double * const wallVelocity,int xlength);
  
  #endif
  
  