add default constructors

src/native/v1_2/request/asset.rs

@@ -32,3 +32,29 @@ pub struct Asset {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub ext: Option<serde_utils::Ext>,
 }
+
+impl Asset {
+    pub fn new(id: u32, required: bool) -> Self {
+        Asset {
+            id,
+            required,
+            title: None,
+            image: None,
+            video: None,
+            data: None,
+            ext: None,
+        }
+    }
+
+    pub fn new_title(id: u32, required: bool, title: Title) -> Self {
+        let mut asset = Asset::new(id, required);
+        asset.title = Some(title);
+        asset
+    }
+
+    pub fn new_image(id: u32, required: bool, image: Image) -> Self {
+        let mut asset = Asset::new(id, required);
+        asset.image = Some(image);
+        asset
+    }
+}

src/native/v1_2/request/image.rs

@@ -2,7 +2,7 @@ use serde_utils;
 
 use super::image_type::ImageTypeID;
 
-#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
 pub struct Image {
     #[serde(rename = "type", skip_serializing_if = "Option::is_none")]
     pub type_id: Option<ImageTypeID>,
@@ -25,3 +25,9 @@ pub struct Image {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub ext: Option<serde_utils::Ext>,
 }
+
+impl Image {
+    pub fn new() -> Self {
+        Default::default()
+    }
+}

src/native/v1_2/request/request.rs

@@ -7,7 +7,7 @@ use super::context_type::ContextTypeID;
 use super::context_sub_type::ContextSubTypeID;
 use super::asset::Asset;
 
-#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default)]
 pub struct Request {
     #[serde(rename = "ver", skip_serializing_if = "Option::is_none")]
     pub version: Option<String>,
@@ -39,3 +39,9 @@ pub struct Request {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub ext: Option<serde_utils::Ext>,
 }
+
+impl Request {
+    pub fn new() -> Self {
+        Default::default()
+    }
+}

src/native/v1_2/request/title.rs

@@ -8,3 +8,12 @@ pub struct Title {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub ext: Option<serde_utils::Ext>,
 }
+
+impl Title {
+    pub fn new(length: u32) -> Self {
+        Title {
+            length,
+            ext: None,
+        }
+    }
+}

src/v2_5/imp.rs

@@ -86,6 +86,28 @@ pub struct Imp {
     pub ext: Option<serde_utils::Ext>,
 }
 
+impl Imp {
+    pub fn new(id: String) -> Self {
+        Imp {
+            id,
+            metric: vec![],
+            banner: None,
+            video: None,
+            audio: None,
+            native: None,
+            pmp: None,
+            display_manager: None,
+            display_manager_ver: None,
+            interstitial: None,
+            tag_id: None,
+            bid_floor: None,
+            bid_floor_cur: None,
+            secure: None,
+            ext: None,
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/v2_5/native.rs

@@ -27,3 +27,15 @@ pub struct Native {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub ext: Option<serde_utils::Ext>,
 }
+
+impl Native {
+    pub fn new(request: String) -> Self {
+        Native {
+            request,
+            version: None,
+            api: vec![],
+            blocked_attrs: vec![],
+            ext: None,
+        }
+    }
+}