class_docstr: Test class for FirehoseClient
docstr: FirehoseClient - Load From Config
code: def test_load_from_config(self):
      """FirehoseClient - Load From Config"""
      with patch(
          "boto3.client"
      ):  # patch to speed up unit tests slightly
          client = FirehoseClient.load_from_config(
              prefix="unit-test",
              firehose_config={"enabled": True},
              log_sources=None,
          )
          assert_equal(isinstance(client, FirehoseClient), True)
  
imports: from botocore.exceptions import ClientError
  from mock import Mock, patch
  from nose.tools import assert_equal
  from streamalert.shared.firehose import FirehoseClient
label_desc: Use image node_id 25 for calling the TestFirehoseClient obj's underlying member method code with example usage: obj.test_load_from_config() without return types