#fixed code
                              @Test
  public void testCustomPromptHandler() {
    sqlLine.runCommands(new DispatchCallback(),
        "!connect "
            + SqlLineArgsTest.ConnectionSpec.H2.url + " "
            + SqlLineArgsTest.ConnectionSpec.H2.username + " \"\"",
        "!prompthandler sqlline.extensions.CustomPromptHandler");

    assertThat(sqlLine.getPromptHandler().getPrompt().toAnsi(),
        is("my_app (PUBLIC)>"));

    sqlLine.runCommands(new DispatchCallback(), "!prompthandler default");

    assertThat(sqlLine.getPromptHandler().getPrompt().toAnsi(),
        is("0: jdbc:h2:mem:> "));

    sqlLine.getDatabaseConnection().close();
  }
#vulnerable code 
                              @Test
  public void testCustomPromptHandler() {
    SqlLine sqlLine = new SqlLine();
    sqlLine.runCommands(new DispatchCallback(),
        "!connect "
            + SqlLineArgsTest.ConnectionSpec.H2.url + " "
            + SqlLineArgsTest.ConnectionSpec.H2.username + " \"\"",
        "!prompthandler sqlline.extensions.CustomPromptHandler");

    assertThat(sqlLine.getPromptHandler().getPrompt().toAnsi(),
        is("my_app (PUBLIC)>"));

    sqlLine.runCommands(new DispatchCallback(), "!prompthandler default");

    assertThat(sqlLine.getPromptHandler().getPrompt().toAnsi(),
        is("0: jdbc:h2:mem:> "));

    sqlLine.getDatabaseConnection().close();
  } 
                            #location 18 
                            #vulnerability type NULL_DEREFERENCE