class_docstr: Generic GRIB file handler.
class_docstr_tok: ["Generic","GRIB","file","handler","."]
docstr: Get area definition for message.
  
  If latlong grid then convert to valid eqc grid.
docstr_tok: ["Get","area","definition","for","message",".","If","latlong","grid","then","convert","to","valid","eqc","grid","."]
code: def get_area_def(self, dsid):
      """Get area definition for message.
  
      If latlong grid then convert to valid eqc grid.
  
      """
      msg = self._get_message(self._msg_datasets[dsid])
      try:
          return self._area_def_from_msg(msg)
      except (RuntimeError, KeyError):
          raise RuntimeError("Unknown GRIB projection information")
  
imports: import logging
  from datetime import datetime
  import dask.array
  import numpy
  import pygrib
  import xarray
  from pyproj import Proj
  from pyresample import geometry
  from satpy.dataset import DataQuery
  from satpy.readers.file_handlers import BaseFileHandler
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 18 for calling the GRIBFileHandler obj's underlying member method code with example usage: obj.get_area_def(dsid) and returns: self