class_docstr: Keeps track of strings to add to string_table in pprof proto.
docstr: Returns a list of strings to store in pprof's string_table.
docstr_tok: ["Returns","a","list","of","strings","to","store","in","pprof","'s","string_table","."]
code: def string_table(self):
      """Returns a list of strings to store in pprof's string_table."""
      return self._string_table
  
imports: from collections import defaultdict
  from collections import namedtuple
  import gzip
  import os
  import string
  import sys
  import time
  from proto import profile_pb2
label_desc: Use image node_id 4 for calling the StringTable obj's underlying member method code with example usage: obj.string_table() and returns: self