code: def test_exprstring(self):
      tcl = self.interp
      tcl.call("set", "a", 3)
      tcl.call("set", "b", 6)
  
      def check(expr, expected):
          result = tcl.exprstring(expr)
          self.assertEqual(result, expected)
          self.assertIsInstance(result, str)
  
      self.assertRaises(TypeError, tcl.exprstring)
      self.assertRaises(TypeError, tcl.exprstring, "8.2", "+6")
      self.assertRaises(TypeError, tcl.exprstring, b"8.2 + 6")
      self.assertRaises(TclError, tcl.exprstring, "spam")
      check("", "0")
      check("8.2 + 6", "14.2")
      check("3.1 + $a", "6.1")
      check('2 + "$a.$b"', "5.6")
      check('4*[llength "6 2"]', "8")
      check('{word one} < "word $a"', "0")
      check("4*2 < 7", "0")
      check("hypot($a, 4)", "5.0")
      check("5 / 4", "1")
      check("5 / 4.0", "1.25")
      check('5 / ( [string length "abcd"] + 0.0 )', "1.25")
      check("20.0/5.0", "4.0")
      check('"0x03" > "2"', "1")
      check('[string length "a\xbd\u20ac"]', "3")
      check(r'[string length "a\xbd\u20ac"]', "3")
      check('"abc"', "abc")
      check('"a\xbd\u20ac"', "a\xbd\u20ac")
      check(r'"a\xbd\u20ac"', "a\xbd\u20ac")
      check(r'"a\0b"', "a\x00b")
      check("2**64", str(2**64))
  
imports: import unittest
  import subprocess
  import sys
  import os
  from test import support
  from test.support import import_helper
  from test.support import os_helper
  import tkinter
  from tkinter import Tcl
  from _tkinter import TclError
label_desc: Use image node_id 29 for calling the TclTest obj's underlying member method code with example usage: obj.test_exprstring() without return types