def log(event = nil, timestamp = Time.now, **fields)
      ts = ::Instana::Util.time_to_ms(timestamp).to_s
      if custom?
        @data[:data][:sdk][:custom][:logs][ts] = fields
        @data[:data][:sdk][:custom][:logs][ts][:event] = event
      else
        set_tags(:log => fields)
      end
    rescue StandardError => e
      Instana.logger.debug "#{__method__}:#{File.basename(__FILE__)}:#{__LINE__}: #{e.message}"
    end
def log(event = nil, timestamp = Time.now, **fields)
      ts = ::Instana::Util.time_to_ms(timestamp).to_s
      if custom?
        @data[:data][:sdk][:custom][:logs][ts] = fields
        @data[:data][:sdk][:custom][:logs][ts][:event] = event
      else
        set_tags(:log => fields)
      end
    rescue StandardError => e
      Instana.logger.debug "#{__method__}:#{File.basename(__FILE__)}:#{__LINE__}: #{e.message}"
    end
Add a log entry to this span
 Spec: OpenTracing API

 @param event [String] event name for the log
 @param timestamp [Time] time of the log
 @param fields [Hash] Additional information to log