class_docstr: Keeps track of `Sample` protos for pprof profile.
  
  Samples store the following statistics in order:
  count, all_time, op_time
docstr: Constructor.
  
  Args:
    string_table: A `StringTable` object.
docstr_tok: ["Constructor",".","Args",":","string_table",":","A","`","StringTable","`","object","."]
code: def __init__(self, string_table):
      """Constructor.
  
      Args:
        string_table: A `StringTable` object.
      """
      self._string_table = string_table
      # TODO(annarev): figure out if location is unique for each node name.
      # If not, also key this dictionary based on location ids.
      self._node_name_to_sample = {}
  
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 1 to create a new Samples object from inherited base classes: object with example: obj = Samples(string_table)