Hook name: $returned_one Hook type: filter Plugin ref: WordPress develop tests Sourcefile: File ref: Tests_Hooks_ApplyFilters::test_apply_filters_with_multiple_calls() – Description: Parameters: Deprecated?: No API Letters: $,O Invokers 1 to 2 of 2 Tests_Hooks_ApplyFilters::test_apply_filters_with_multiple_calls() – Tests_WP_Hook_Apply_Filters::test_apply_filters_with_multiple_calls() – Implementers