text: #include "multiply_by_two.h"
  
  static void* _read(Peripheral* self)
  {
      return self->data;
  }
  
  static void _write(Peripheral* self, void* data)
  {
      *(double*)self->data = *(double*)data * 2;;
  }
  
  Peripheral create_multiply_by_two()
  {
      return new_Peripheral(&_read, &_write, DOUBLE);
  }
  