class_docstr: Test class for SlackOutput
class_docstr_tok: ["Test","class","for","SlackOutput"]
docstr: SlackOutput - Split Attachment, On Newline
docstr_tok: ["SlackOutput","-","Split","Attachment",",","On","Newline"]
code: def test_split_attachment_text_newline(self):
      """SlackOutput - Split Attachment, On Newline"""
      message = {"messages": "test\n" * 800}
      result = list(SlackOutput._split_attachment_text(message))
      assert_equal(len(result[0]), 3996)
  
imports: from collections import Counter, OrderedDict
  from mock import patch, Mock, MagicMock
  from nose.tools import assert_equal, assert_false, assert_true, assert_set_equal
  from streamalert.alert_processor.helpers import compose_alert
  from streamalert.alert_processor.outputs.slack import SlackOutput
  from tests.unit.streamalert.alert_processor.helpers import get_random_alert, get_alert
label_desc: Use image node_id 17 for calling the TestSlackOutput obj's underlying member method code with example usage: obj.test_split_attachment_text_newline() without return types