class_docstr: MERSI-2/MERSI-LL L1B file reader.
code: def _get_single_slope_intercept(self, slope, intercept, cal_index):
      try:
          # convert scalar arrays to scalar
          return slope.item(), intercept.item()
      except ValueError:
          # numpy array but has more than one element
          return slope[cal_index], intercept[cal_index]
  
file_path: satpy/satpy/readers/mersi_l1b.py
imports: from datetime import datetime
  import dask.array
  import numpy
  from pyspectral.blackbody import blackbody_wn_rad2temp
  from satpy.readers.hdf5_utils import HDF5FileHandler
label_desc: Use image node_id 5 for calling the MERSIL1B obj's underlying member method code with example usage: obj._get_single_slope_intercept(slope, intercept, cal_index) and returns: slope,  intercept, slope,  intercept