Allow position to be Null

src/models/eta.rs

@@ -51,7 +51,7 @@ pub struct Eta {
     #[serde(rename = "isFlt")]
     pub is_flt: String,
     pub flags: Option<String>,
-    pub lat: String,
+    pub lat: Option<String>,
-    pub lon: String,
+    pub lon: Option<String>,
-    pub heading: String,
+    pub heading: Option<String>,
 }

src/models/follow.rs

@@ -9,9 +9,9 @@ pub struct FollowRequest {
 
 #[derive(Deserialize, Debug, Default)]
 pub struct Position {
-    pub lat: String,
+    pub lat: Option<String>,
-    pub lon: String,
+    pub lon: Option<String>,
-    pub heading: String,
+    pub heading: Option<String>,
 }
 
 #[derive(Deserialize, Debug)]

src/models/train.rs

@@ -23,7 +23,7 @@ pub struct Train {
     #[serde(rename = "isDly")]
     pub is_dly: String,
     pub flags: Option<String>,
-    pub lat: String,
+    pub lat: Option<String>,
-    pub lon: String,
+    pub lon: Option<String>,
-    pub heading: String,
+    pub heading: Option<String>,
 }