code: def _find_strings(filename, encoding=None):
      """Return a dict of possible docstring positions.
  
      The dict maps line numbers to strings.  There is an entry for
      line that contains only a string or a part of a triple-quoted
      string.
      """
      d = {}
      # If the first token is a string, then it's the module docstring.
      # Add this special case so that the test in the loop passes.
      prev_ttype = token.INDENT
      with open(filename, encoding=encoding) as f:
          tok = tokenize.generate_tokens(f.readline)
          for ttype, tstr, start, end, line in tok:
              if ttype == token.STRING:
                  if prev_ttype == token.INDENT:
                      sline, scol = start
                      eline, ecol = end
                      for i in range(sline, eline + 1):
                          d[i] = 1
              prev_ttype = ttype
      return d
  
imports: import io
  import linecache
  import os
  import sys
  import sysconfig
  import token
  import tokenize
  import inspect
  import gc
  import dis
  import pickle
  from time import monotonic
  import threading
label_desc: Use image node_id 5 for calling a global function with example usage: _find_strings(filename, encoding) and returns: d