class_docstr: Class for writing matlab 4 format files 
class_docstr_tok: ["Class","for","writing","matlab","4","format","files"]
code: def __init__(self, file_stream, oned_as=None):
      self.file_stream = file_stream
      if oned_as is None:
          oned_as = "row"
      self.oned_as = oned_as
      self._matrix_writer = None
  
imports: import sys
  import warnings
  import numpy
  import scipy.sparse
  from ._miobase import MatFileReader, docfiller, matdims, read_dtype, convert_dtypes, arr_to_chars, arr_dtype_number
  from ._mio_utils import squeeze_element, chars_to_strings
  from functools import reduce
label_desc: Use image node_id 1 to create a new MatFile4Writer object  with example: obj = MatFile4Writer(file_stream, oned_as)