NewProxyQueryService creates a new proxy query service with a log.

AuthorizationService manages authorizations.

ProxyQueryService logs the request but does not write to the writer.

Span implements opentracing.Span, all Spans must be created using the Tracer.

SpanContext implements opentracing.SpanContext, all span contexts must be created using the Tracer.

Tracer implements opentracing.Tracer and logs each span as its own log.