def b(byte_index, bit_range=nil)
      byte_num = self[byte_index].unpack("C")[0]
      return byte_num unless bit_range
      return sub_integer(byte_num, bit_range)
    end
def b(byte_index, bit_range=nil)
      byte_num = self[byte_index].unpack("C")[0]
      return byte_num unless bit_range
      return sub_integer(byte_num, bit_range)
    end
"byte_string" is string encoded as ASCII_8BIT (BINARY).
 Return Integer that is converted from bits specified by "bit_range" (arg2) in
 byte specified by "byte_index" (arg1).

 *Warning*: Bit index is from right to left. So, LSB's position is 0, MSB's is 7