class_docstr: Generic matlab matrix writing class 
code: def write_cells(self, arr):
      self.write_header(matdims(arr, self.oned_as), mxCELL_CLASS)
      # loop over data, column major
      A = np.atleast_2d(arr).flatten("F")
      for el in A:
          self.write(el)
  
imports: import os
  import time
  import sys
  import zlib
  from io import BytesIO
  import warnings
  import numpy
  import scipy.sparse
  from ._byteordercodes import native_code, swapped_code
  from ._miobase import MatFileReader, docfiller, matdims, read_dtype, arr_to_chars, arr_dtype_number, MatWriteError, MatReadError, MatReadWarning
  from ._mio5_utils import VarReader5
  from ._mio5_params import MatlabObject, MatlabFunction, MDTYPES, NP_TO_MTYPES, NP_TO_MXTYPES, miCOMPRESSED, miMATRIX, miINT8, miUTF8, miUINT32, mxCELL_CLASS, mxSTRUCT_CLASS, mxOBJECT_CLASS, mxCHAR_CLASS, mxSPARSE_CLASS, mxDOUBLE_CLASS, mclass_info, mat_struct
  from ._streams import ZlibInputStream
label_desc: Use image node_id 14 for calling the VarWriter5 obj's underlying member method code with example usage: obj.write_cells(arr) without return types