code: def test_merge_required_outputs_exists():
      """Shared - Merge Required Outputs, Has Existing"""
      # A simple user config with an exist aws-firehose output
      # that will be merged with required outputs
      users_config = {
          "aws-firehose": {"notalerts": "resource_name"},
          "aws-sns": {"topic": "my-sns-topic"},
          "slack": ["slack_output"],
      }
  
      outputs = resources.merge_required_outputs(users_config, "test")
  
      assert_equal(len(outputs), 3)
  
      expected_fh = {
          "notalerts": "resource_name",
          "alerts": "test_streamalert_alert_delivery",
      }
  
      assert_count_equal(outputs["aws-firehose"], expected_fh)
  
imports: from nose.tools import assert_equal, assert_count_equal
  from streamalert.shared import resources
label_desc: Use image node_id 3 for calling a global function with example usage: test_merge_required_outputs_exists() without return types