code: def test_trace_callback_content(self):
      # set_trace_callback() shouldn't produce duplicate content (bpo-26187)
      traced_statements = []
  
      def trace(statement):
          traced_statements.append(statement)
  
      queries = ["create table foo(x)", "insert into foo(x) values(1)"]
      self.addCleanup(unlink, TESTFN)
      con1 = sqlite.connect(TESTFN, isolation_level=None)
      con2 = sqlite.connect(TESTFN)
      try:
          con1.set_trace_callback(trace)
          cur = con1.cursor()
          cur.execute(queries[0])
          con2.execute("create table bar(x)")
          cur.execute(queries[1])
      finally:
          con1.close()
          con2.close()
      self.assertEqual(traced_statements, queries)
  
imports: import contextlib
  import sqlite3
  import unittest
  from test.support.os_helper import TESTFN, unlink
  from .util import memory_database, cx_limit, with_tracebacks
  from .util import MemoryDatabaseMixin
label_desc: Use image node_id 5 for calling the TraceCallbackTests obj's underlying member method code with example usage: obj.test_trace_callback_content() without return types