Jetpack_Conditional::is_met() – Returns `true` when the Jetpack plugin exists on this WordPress installation.
jsonSerialize() – Returns an array of parameters to serialize when this is serialized with json_encode().
ORM::_join_if_not_empty() – Wrapper around PHP’s join function which only adds the pieces if they are not empty.
WPSEO_Schema::json_ld() – JSON LD output function that the functions for specific code can hook into.
WPSEO_Utils::javascript_console_notification() – Register a notification to be shown in the JavaScript console.