implement default spatial reference as wkid 3857

src/spatial_reference.rs

@@ -4,11 +4,23 @@ use serde_with::skip_serializing_none;
 
 /// Read more on [Esri docs site](https://developers.arcgis.com/documentation/common-data-types/geometry-objects.htm#GUID-DFF0E738-5A42-40BC-A811-ACCB5814BABC)
 #[skip_serializing_none]
-#[derive(Serialize, Deserialize, Debug, Clone, Default)]
+#[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct SpatialReference {
     pub wkid: Option<u32>,
     pub latest_wkid: Option<u32>,
     pub vcs_wkid: Option<u32>,
     pub latest_vcs_wkid: Option<u32>,
     pub wkt: Option<String>,
 }
+
+impl Default for SpatialReference {
+    fn default() -> Self {
+        Self {
+            wkid: Some(3857_u32),
+            latest_wkid: None,
+            vcs_wkid: None,
+            latest_vcs_wkid: None,
+            wkt: None,
+        }
+    }
+}