public SpanTracer(Medidata.ZipkinTracer.Core.Collector.SpanCollector spanCollector, string serviceName, ServiceEndpoint zipkinEndpoint)
        {
            if ( spanCollector == null) 
            {
                throw new ArgumentNullException("spanCollector is null");
            }

            if ( String.IsNullOrEmpty(serviceName)) 
            {
                throw new ArgumentNullException("serviceName is null or empty");
            }

            if ( zipkinEndpoint == null) 
            {
                throw new ArgumentNullException("zipkinEndpoint is null");
            }

            this.serviceName = serviceName;
            this.spanCollector = spanCollector;
            this.zipkinEndpoint = zipkinEndpoint;
        }
        public SpanTracer(Medidata.ZipkinTracer.Core.Collector.SpanCollector spanCollector, string serviceName, ServiceEndpoint zipkinEndpoint)
        {
            if (spanCollector == null)
            {
                throw new ArgumentNullException("spanCollector is null");
            }

            if (String.IsNullOrEmpty(serviceName))
            {
                throw new ArgumentNullException("serviceName is null or empty");
            }

            if (zipkinEndpoint == null)
            {
                throw new ArgumentNullException("zipkinEndpoint is null");
            }

            this.serviceName    = serviceName;
            this.spanCollector  = spanCollector;
            this.zipkinEndpoint = zipkinEndpoint;
        }