code: def crc_update(crc, data):
      """Update CRC-32C checksum with data.
  
      Args:
        crc: 32-bit checksum to update as long.
        data: byte array, string or iterable over bytes.
      Returns:
        32-bit updated CRC-32C as long.
      """
  
      if type(data) != array.array or data.itemsize != 1:
          buf = array.array("B", data)
      else:
          buf = data
  
      crc ^= _MASK
      for b in buf:
          table_index = (crc ^ b) & 0xFF
          crc = (CRC_TABLE[table_index] ^ (crc >> 8)) & _MASK
      return crc ^ _MASK
  
file_path: tensorboard/tensorboard/compat/tensorflow_stub/pywrap_tensorflow.py
imports: import array
  import struct
  from .None import errors
  from .io import gfile
label_desc: Use image node_id 5 for calling a global function with example usage: crc_update(crc, data) and returns: unknown