text: #ifndef UTILS_H
  #define UTILS_H
  
  #define NO_IMPORT_ARRAY
  #include "common.h"
  
  int not_float64_vector(PyArrayObject *);
  npy_intp ndarray_dim(PyArrayObject *);
  double get_double_at(PyArrayObject *, npy_intp);
  double* reverse_vector(const double*, npy_intp);
  
  #endif