docstr: Register two different collation functions under the same name.
  Verify that the last one is actually used.
code: def test_collation_register_twice(self):
      """
      Register two different collation functions under the same name.
      Verify that the last one is actually used.
      """
      con = self.con
      con.create_collation("mycoll", lambda x, y: (x > y) - (x < y))
      con.create_collation("mycoll", lambda x, y: -((x > y) - (x < y)))
      result = con.execute(
          """
              select x from (select 'a' as x union select 'b' as x) order by x collate mycoll
              """
      ).fetchall()
      self.assertEqual(result[0][0], "b")
      self.assertEqual(result[1][0], "a")
  
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 7 for calling the CollationTests obj's underlying member method code with example usage: obj.test_collation_register_twice() without return types