H5P_GET_FILE_IMAGE_CALLBACKS retrieves the callback routines set for working with file images opened with the file access property list
The callbacks must have been previously set with H5P_SET_FILE_IMAGE_CALLBACKS in the file access property list.
Upon the successful return of H5P_SET_FILE_IMAGE_CALLBACKS, the fields in the instance of the
H5_file_image_callbacks_t struct pointed to by
callbacks_ptr will contain the same values as were passed in the most recent H5P_SET_FILE_IMAGE_CALLBACKS call for the file access property list