void **allocateArray(size_t nmemb, size_t *membsize) {
  void *array;
  unsigned long **arr;

  array = calloc(nmemb, sizeof(void*));
  if( !array ) {
    perror("malloc: ");
    return NULL;
  }
  arr = (unsigned long**)array;

  for(int i = 0; i < nmemb; ++i) {
    arr[i] = malloc(membsize[i]);
    if( !arr[i] ) {
      perror("malloc: ");
      return NULL;
    }

    memset(arr[i], 0, membsize[i]);
  }
  return (void**)array;
}