class_docstr: Represent a single revision of a GCS Object.
class_docstr_tok: ["Represent","a","single","revision","of","a","GCS","Object","."]
docstr: Return the value for the x-goog-hash header.
docstr_tok: ["Return","the","value","for","the","x-goog-hash","header","."]
code: def x_goog_hash_header(self):
      """Return the value for the x-goog-hash header."""
      hashes = {
          "md5": self.metadata.get("md5Hash", ""),
          "crc32c": self.metadata.get("crc32c", ""),
      }
      hashes = [f"{key}={val}" for key, val in hashes.items() if val]
      return ",".join(hashes)
  
imports: import base64
  import crc32c
  import error_response
  import hashlib
  import json
  import struct
  import testbench_utils
  import time
label_desc: Use image node_id 8 for calling the GcsObjectVersion obj's underlying member method code with example usage: obj.x_goog_hash_header() and returns: str