class_docstr: Test class for SESOutput
docstr: SESOutput - Override body string
docstr_tok: ["SESOutput","-","Override","body","string"]
code: def test_override_default_body_string(self):
      """SESOutput - Override body string"""
      rule_name = "test_override_body_string"
  
      alert = get_random_alert(10, rule_name, omit_rule_desc=True)
      output = MagicMock(spec=SESOutput)
      alert_publication = compose_alert(alert, output, self.DESCRIPTOR)
  
      alert_publication["@aws-ses.body"] = "i am a test"
  
      msg = SESOutput._build_email(alert, alert_publication, self.CREDS)
  
      # Tests
      payloads = msg.get_payload()
      for payload in payloads:
          if isinstance(payload, MIMEText):
              assert_equal(payload.get_payload(), "i am a test")
              break
      else:
          # Raise an error if no payload of type MIMEText is found
          raise AssertionError
  
imports: from email.mime.application import MIMEApplication
  from email.mime.text import MIMEText
  import boto3
  from mock import MagicMock, Mock, patch
  from moto import mock_kinesis, mock_s3, mock_sns, mock_sqs, mock_ses
  from nose.tools import assert_equal, assert_false, assert_is_not_none, assert_true
  from streamalert.alert_processor.helpers import compose_alert
  from streamalert.alert_processor.outputs.output_base import OutputProperty
  from streamalert.alert_processor.outputs import aws
  from streamalert.alert_processor.outputs.aws import AWSOutput, KinesisFirehoseOutput, LambdaOutput, S3Output, SESOutput, SNSOutput, SQSOutput, CloudwatchLogOutput, LambdaOutputV2
  from tests.unit.streamalert.alert_processor import CONFIG, MOCK_ENV, REGION
  from tests.unit.streamalert.alert_processor.helpers import get_alert, get_random_alert
label_desc: Use image node_id 10 for calling the TestSESOutput obj's underlying member method code with example usage: obj.test_override_default_body_string() without return types