(20250128) Handling Null in WhatsApp Nimbus's 'msg' field.

utils_v2/whatsapp/nimbus/models/send_message_response.py

@@ -99,9 +99,10 @@ class NimbusWhatsappSendMessageResponse(BaseModel):
         frozen = True
     )
 
-    message: str = Field(
+    message: str | None = Field(
         description = "The actual message to send to the recipient(s).",
-        frozen = True
+        frozen = True,
+        default = None
     )
 
     pdfUrl: str | None = Field(
@@ -206,7 +207,7 @@ class NimbusWhatsappSendMessageResponse(BaseModel):
         # Start with the bare minimum:
         api_input = {
             "mobile": ",".join(self.recipientNo),
-            "msg": self.message
+            "msg": self.message or " "
         }
 
         # Add the optional media elements: