old_contents: from flask import request
  
  from zeus import auth
  
  
  class HeaderAuthentication(object):
      def authenticate(self):
          return auth.get_tenant_from_headers(request.headers)
  
  
  class SessionAuthentication(object):
      def authenticate(self):
          user = auth.get_current_user()
          if not user:
              return None
  
          return auth.Tenant.from_user(user)
  
new_contents: from flask import request
  
  from zeus import auth
  from zeus.utils.sentry import span
  
  
  class HeaderAuthentication(object):
      @span("auth.header")
      def authenticate(self):
          return auth.get_tenant_from_headers(request.headers)
  
  
  class SessionAuthentication(object):
      @span("auth.session")
      def authenticate(self):
          user = auth.get_current_user()
          if not user:
              return None
  
          return auth.Tenant.from_user(user)
  
subject: Add span for authentication mechanism (#403)