TextMessageV2 Substitution should be interface instead of struct

[SarawinT]

Expected Behavior

To use Substitution field in TextMessageV2 should be able to use any of the substition type.

Current Behavior

Cannot use any of the substitions type (eg. MentionSubstitutionObject) as value in map of Substitution to push message.

Fix

Change type of Substitution from map[string]SubstitutionObject to map[string]SubstitutionObjectInterface in File: linebot/messaging_api/model_text_message_v2.go Line: 50 (or wherever it's defined) seems to fixed the issue.

[habara-k]

Thank you very much for your report and for using the line-bot-sdk-go.

We have verified the behavior on our side, and indeed, changing the type of Substitution from map[string]SubstitutionObject to map[string]SubstitutionObjectInterface resolves the issue as you described. We will apply this fix accordingly.

We sincerely apologize for any inconvenience this may have caused, and we truly appreciate your feedback.