code: def read_float8(f):
      r"""
      >>> import io, struct
      >>> raw = struct.pack(">d", -1.25)
      >>> raw
      b'\xbf\xf4\x00\x00\x00\x00\x00\x00'
      >>> read_float8(io.BytesIO(raw + b"\n"))
      -1.25
      """
  
      data = f.read(8)
      if len(data) == 8:
          return _unpack(">d", data)[0]
      raise ValueError("not enough data in stream to read float8")
  
imports: import codecs
  import io
  import pickle
  import re
  import sys
  from struct import unpack
  from pickle import decode_long
label_desc: Use image node_id 22 for calling a global function with example usage: read_float8(f) and returns: _unpack