nl_tokens: A tracer that records directly to Zipkin Query HTTP API .
pl_tokens: function RawZipkinQueryServiceHTTPTracer ( traceUrl ) { if ( traceUrl . charAt ( traceUrl . <mask> - 1 ) === '/' ) { traceUrl = traceUrl . slice ( 0 , - 1 ) ; } this . _traceUrl = traceUrl ; EndAnnotationTracer . call ( this , this . sendTraces ) ; }