Intent of operator_equal

All 2 exact tests in this concept. Every test is marked by where it enters the hierarchy.

go.temporal.io/ 2 tests
- server/ 2 tests
  - common/ 2 tests
    
    persistence/ 2 tests
    
    visibility/ 2 tests
    
    store/ 2 tests
    
    elasticsearch/ 2 tests
    
    TestQueryConverter_ConvertKeywordListComparisonExpr/ 2 tests
    
    go.temporal.io/server/common/persistence/visibility/store/elasticsearch/TestQueryConverter_ConvertKeywordListComparisonExpr/operator_equal Introduced here
    
    go.temporal.io/server/common/persistence/visibility/store/elasticsearch/TestQueryConverter_ConvertKeywordListComparisonExpr/operator_not_equal Inherited operator_not_equal