code: def parse_multisig_scriptsig( scriptsig_hex ):
      
      try:
          script_parts = btc_script_deserialize(scriptsig_hex)
      except:
          if os.environ.get("BLOCKSTACK_TEST") == "1":
              traceback.print_exc()
  
          return None
  
      # sanity check 
      return script_parts
docs: Given a scriptsig (as hex), extract the signatures.
      Return list of signatures on success
      Return None on error