text: #ifndef Py_CPYTHON_BYTEARRAYOBJECT_H
  #  error "this header file must not be included directly"
  #endif
  
  /* Object layout */
  typedef struct {
      PyObject_VAR_HEAD
      Py_ssize_t ob_alloc;   /* How many bytes allocated in ob_bytes */
      char *ob_bytes;        /* Physical backing buffer */
      char *ob_start;        /* Logical start inside ob_bytes */
      Py_ssize_t ob_exports; /* How many buffer exports */
  } PyByteArrayObject;
  
  /* Macros, trading safety for speed */
  #define PyByteArray_AS_STRING(self) \
      (assert(PyByteArray_Check(self)), \
       Py_SIZE(self) ? ((PyByteArrayObject *)(self))->ob_start : _PyByteArray_empty_string)
  #define PyByteArray_GET_SIZE(self) (assert(PyByteArray_Check(self)), Py_SIZE(self))
  
  PyAPI_DATA(char) _PyByteArray_empty_string[];
  