class_docstr: Filehandler for angles.
docstr: Load a cartesian file of appropriate type.
docstr_tok: ["Load","a","cartesian","file","of","appropriate","type","."]
code: def _loadcart(self, fname):
      """Load a cartesian file of appropriate type."""
      cartf = xr.open_dataset(
          fname,
          decode_cf=True,
          mask_and_scale=True,
          chunks={"columns": CHUNK_SIZE, "rows": CHUNK_SIZE},
      )
      return cartf
  
imports: import logging
  import os
  import re
  import warnings
  from datetime import datetime
  import dask.array
  import numpy
  import xarray
  from satpy.readers.file_handlers import BaseFileHandler
  from satpy.utils import get_legacy_chunk_size
label_desc: Use image node_id 1 for calling the NCSLSTRAngles obj's underlying member method code with example usage: obj._loadcart(fname) and returns: cartf