Fix incompatibiity with empth result handling.

hub_handler returns Result<Option<R>, Error> for control_child().

tapo/src/api/child_devices/t300_handler.rs

@@ -1,5 +1,5 @@
 use crate::api::HubHandler;
-use crate::error::Error;
+use crate::error::{Error,TapoResponseError};
 use crate::requests::{EmptyParams, GetTriggerLogsParams, TapoParams, TapoRequest};
 use crate::responses::T300Result;
 use crate::responses::{T300Log, TriggerLogsResult};
@@ -25,7 +25,8 @@ impl<'h> T300Handler<'h> {
 
         self.hub_handler
             .control_child(self.device_id.clone(), request)
-            .await
+            .await?
+            .ok_or_else(|| Error::Tapo(TapoResponseError::EmptyResult))
     }
 
     /// Returns a list of trigger logs.
@@ -44,8 +45,12 @@ impl<'h> T300Handler<'h> {
         let child_params = GetTriggerLogsParams::new(page_size, start_id);
         let child_request = TapoRequest::GetTriggerLogs(Box::new(TapoParams::new(child_params)));
 
-        self.hub_handler
-            .control_child(self.device_id.clone(), child_request)
-            .await
+        let result = self
+            .hub_handler
+            .control_child::<TriggerLogsResult<T300Log>>(self.device_id.clone(), child_request)
+            .await?
+            .ok_or_else(|| Error::Tapo(TapoResponseError::EmptyResult));
+
+        Ok(result?)
     }
 }