code: def test_send_bcc_smtp(self, mock_send_mime):
      attachment = tempfile.NamedTemporaryFile()
      attachment.write(b"attachment")
      attachment.seek(0)
      utils.send_email_smtp(
          "to",
          "subject",
          "content",
          app.config,
          files=[attachment.name],
          cc="cc",
          bcc="bcc",
      )
      assert mock_send_mime.called
      call_args = mock_send_mime.call_args[0]
      assert call_args[0] == app.config["SMTP_MAIL_FROM"]
      assert call_args[1] == ["to", "cc", "bcc"]
      msg = call_args[2]
      assert msg["Subject"] == "subject"
      assert msg["From"] == app.config["SMTP_MAIL_FROM"]
      assert len(msg.get_payload()) == 2
      mimeapp = MIMEApplication("attachment")
      assert (
          msg.get_payload()[-1].get_payload() == mimeapp.get_payload()
      )
  
imports: import logging
  import ssl
  import tempfile
  import unittest
  from email.mime.application import MIMEApplication
  from email.mime.image import MIMEImage
  from email.mime.multipart import MIMEMultipart
  from unittest import mock
  from superset import app
  from superset.utils import core
  from tests.integration_tests.base_tests import SupersetTestCase
  from .utils import read_fixture
label_desc: Use image node_id 6 for calling the TestEmailSmtp obj's underlying member method code with example usage: obj.test_send_bcc_smtp(mock_send_mime) without return types