docstr: Verify the pretty-printing of True, False and None
docstr_tok: ["Verify","the","pretty-printing","of","True",",","False","and","None"]
code: def test_singletons(self):
      "Verify the pretty-printing of True, False and None"
      self.assertGdbRepr(True)
      self.assertGdbRepr(False)
      self.assertGdbRepr(None)
  
imports: import re
  import sys
  from test import support
  from .util import BREAKPOINT_FN, GDB_VERSION, run_gdb, setup_module, DebuggerTests
label_desc: Use image node_id 5 for calling the PrettyPrintTests obj's underlying member method code with example usage: obj.test_singletons() without return types