class_docstr: AHI gridded format reader.
  
  This data is flat binary, big endian unsigned short.
  It covers the region 85E -> 205E, 60N -> 60S at variable resolution:
  - 0.005 degrees for Band 3
  - 0.01 degrees for Bands 1, 2 and 4
  - 0.02 degrees for all other bands.
  These are approximately equivalent to 0.5, 1 and 2km.
  
  Files can either be zipped with bz2 compression (like the HSD format
  data), or can be uncompressed flat binary.
docstr: Read raw binary data from file.
docstr_tok: ["Read","raw","binary","data","from","file","."]
code: def _read_data(self, fp_):
      """Read raw binary data from file."""
      return da.from_array(
          np.memmap(
              self.filename,
              offset=fp_.tell(),
              dtype=">u2",
              shape=(self.nlines, self.ncols),
              mode="r",
          ),
          chunks=CHUNK_SIZE,
      )
  
imports: import logging
  import os
  import dask.array
  import numpy
  import xarray
  from appdirs import AppDirs
  from pyresample import geometry
  from satpy.readers.file_handlers import BaseFileHandler
  from satpy.readers.utils import unzip_file
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 10 for calling the AHIGriddedFileHandler obj's underlying member method code with example usage: obj._read_data(fp_) and returns: da