code: def read_string1(f):
      r"""
      >>> import io
      >>> read_string1(io.BytesIO(b"\x00"))
      ''
      >>> read_string1(io.BytesIO(b"\x03abcdef"))
      'abc'
      """
  
      n = read_uint1(f)
      assert n >= 0
      data = f.read(n)
      if len(data) == n:
          return data.decode("latin-1")
      raise ValueError(
          "expected %d bytes in a string1, but only %d remain"
          % (n, len(data))
      )
  
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 9 for calling a global function with example usage: read_string1(f) and returns: data