code: def test_get_metric_fail_invalid_name(self):
      metrics_cache_obj = MetricsCacheYamlImpl(
          os.path.join(dir_path, "metrics.yaml")
      )
      with pytest.raises(merrors.MetricsCacheTypeError) as exc_info:
          metrics_cache_obj.get_metric(None, MetricTypes.GAUGE)
      assert str(exc_info.value) == "`metric_name` must be a str"
  
imports: import os
  import uuid
  import pytest
  import ts.metrics.metric_cache_errors
  from ts.metrics.caching_metric import CachingMetric
  from ts.metrics.dimension import Dimension
  from ts.metrics.metric_cache_yaml_impl import MetricsCacheYamlImpl
  from ts.metrics.metric_type_enum import MetricTypes
label_desc: Use image node_id 4 for calling the TestGetMetrics obj's underlying member method code with example usage: obj.test_get_metric_fail_invalid_name() without return types