class Ougai::Formatters::Pino

def flat_err(data)
  return unless data.key?(:err)
  err = data.delete(:err)
  msg = err[:message]
  data[:type] ||= 'Error'
  data[:msg] ||= msg
  stack = "#{err[:name]}: #{msg}"
  stack += "\n" + (" " * @trace_indent) + err[:stack] if err.key?(:stack)
  data[:stack] ||= stack
end