code: def test_low_cardinality_ratio_rule_low_cardinality_all_nulls_doesnt_match() -> (
      None
  ):  # noqa: D
      rule = ExampleLowCardinalityRule(0.1)
      ctx = create_context_with_counts(100, 1, 100)
  
      signals = rule.process(ctx)
      assert len(signals) == 0
  
file_path: metricflow/metricflow/test/inference/rule/test_rules.py
imports: from __future__ import annotations
  from metricflow.dataflow.sql_column import SqlColumn
  from metricflow.dataflow.sql_table import SqlTable
  from metricflow.inference.context.data_warehouse import ColumnProperties, DataWarehouseInferenceContext, InferenceColumnType, TableProperties
  from metricflow.inference.models import InferenceSignalConfidence, InferenceSignalType
  from metricflow.inference.rule.rules import ColumnMatcherRule, LowCardinalityRatioRule
label_desc: Use image node_id 5 for calling a global function with example usage: test_low_cardinality_ratio_rule_low_cardinality_all_nulls_doesnt_match() without return types