code: def test_async_dont_read_all(self):
      cur = self.conn.cursor()
      cur.execute(
          "select repeat('a', 10000); select repeat('b', 10000)"
      )
  
      # fetch the result
      self.wait(cur)
  
      # it should be the result of the second query
      self.assertEquals(cur.fetchone()[0], "b" * 10000)
  
imports: import gc
  import time
  import unittest
  import warnings
  import psycopg2
  import psycopg2.errors
  from psycopg2 import extensions
  from .testutils import ConnectingTestCase, StringIO, skip_before_postgres, skip_if_crdb, crdb_version, slow
label_desc: Use image node_id 18 for calling the AsyncTests obj's underlying member method code with example usage: obj.test_async_dont_read_all() without return types