class_docstr: Test class for LambdaOutput
docstr: Setup before each method
docstr_tok: ["Setup","before","each","method"]
code: def setup(self, provider_constructor):
      """Setup before each method"""
      provider = MagicMock()
      provider_constructor.return_value = provider
      provider.load_credentials = Mock(
          side_effect=lambda x: self.CREDS
          if x == self.DESCRIPTOR
          else None
      )
  
      self._provider = provider
      self._dispatcher = LambdaOutputV2(None)
  
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 1 for calling the TestLambdaV2Output obj's underlying member method code with example usage: obj.setup(provider_constructor) without return types