class_docstr: Backend storage for our "array of bits" using a file in which we seek
class_docstr_tok: ["Backend","storage","for","our","``","array","of","bits","''","using","a","file","in","which","we","seek"]
docstr: clear bit number bitno - set it to false
code: def clear(self, bitno):
      """clear bit number bitno - set it to false"""
  
      byteno, bit_within_byteno = divmod(bitno, 8)
      mask = 1 << bit_within_byteno
      os.lseek(self.file_, byteno, os.SEEK_SET)
      byte = os.read(self.file_, 1)[0]
      byte &= File_seek_backend.effs - mask
      os.lseek(self.file_, byteno, os.SEEK_SET)
      os.write(self.file_, bytes([byte]))
  
imports: import array
  import math
  import os
  import random
label_desc: Use image node_id 4 for calling the File_seek_backend obj's underlying member method code with example usage: obj.clear(bitno) without return types