text: #include <assert.h>
  #include "sheep.h"
  
  int main() {
      mammal_t *s = make_sheep(50);
      s->print(s);
      s->speak();
  
      assert(s->getWeight(s) == 50);
  
      s->setWeight(s, 200);
      assert(s->getWeight(s) == 200);
  
      s->delete(s);
  
      return 0;
  }
  