in lib/skywalking/segment_ref.lua [75:86]
function _M.serialize(ref)
local encodedRef = '1'
.. '-' .. encode_base64(ref.trace_id)
.. '-' .. encode_base64(ref.segment_id)
.. '-' .. ref.span_id
.. '-' .. encode_base64(ref.parent_service)
.. '-' .. encode_base64(ref.parent_service_instance)
.. '-' .. encode_base64(ref.parent_endpoint)
.. '-' .. encode_base64(ref.address_used_at_client)
return encodedRef
end