  ContextImpl(Http::RequestHeaderMap& headers, Tracing::Span& parent_span,
              Verifier::Callbacks* callback)
      : headers_(headers), parent_span_(parent_span), callback_(callback) {}
  ContextImpl(Http::RequestHeaderMap& headers, Tracing::Span& parent_span,
              Verifier::Callbacks* callback)
      : headers_(headers), parent_span_(parent_span), callback_(callback) {}