code: def test_getdouble(self):
      tcl = self.interp.tk
      self.assertEqual(tcl.getdouble(" 42 "), 42.0)
      self.assertEqual(tcl.getdouble(" 42.5 "), 42.5)
      self.assertEqual(tcl.getdouble(42.5), 42.5)
      self.assertEqual(tcl.getdouble(42), 42.0)
      self.assertRaises(TypeError, tcl.getdouble)
      self.assertRaises(TypeError, tcl.getdouble, "42.5", "10")
      self.assertRaises(TypeError, tcl.getdouble, b"42.5")
      self.assertRaises(TclError, tcl.getdouble, "a")
      self.assertRaises(
          (TypeError, ValueError, TclError), tcl.getdouble, "42.5\0"
      )
      self.assertRaises(
          (UnicodeEncodeError, ValueError, TclError),
          tcl.getdouble,
          "42.5\ud800",
      )
  
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 21 for calling the TclTest obj's underlying member method code with example usage: obj.test_getdouble() without return types