code: def sample_metrics() -> dict["SqlMetric", dict[str, Any]]:
      from superset.connectors.sqla.models import SqlMetric
  
      return {
          SqlMetric(
              metric_name="cnt",
              expression="COUNT(*)",
              metric_type="COUNT",
          ): {
              "name": "cnt",
              "expression": "COUNT(*)",
              "extra_json": '{"metric_type": "COUNT"}',
              "type": "UNKNOWN",
              "advanced_data_type": None,
              "is_additive": True,
              "is_aggregation": True,
              "is_filterable": False,
              "is_physical": False,
          },
          SqlMetric(
              metric_name="avg revenue",
              expression="AVG(revenue)",
              metric_type="AVG",
          ): {
              "name": "avg revenue",
              "expression": "AVG(revenue)",
              "extra_json": '{"metric_type": "AVG"}',
              "type": "UNKNOWN",
              "advanced_data_type": None,
              "is_additive": False,
              "is_aggregation": True,
              "is_filterable": False,
              "is_physical": False,
          },
      }
  
imports: from typing import Any, TYPE_CHECKING
  import pytest
label_desc: Use image node_id 3 for calling a global function with example usage: sample_metrics() and returns: dict