Add is_kind for BaseExt

src/base.rs

@@ -336,6 +336,31 @@ pub trait BaseExt<Kind>: AsBase<Kind> {
         self.base_ref().kind.as_ref()
     }
 
+    /// Check if the provide Kind is equal to the object's Kind
+    ///
+    /// ```rust
+    /// # fn main() -> Result<(), anyhow::Error> {
+    /// use activitystreams_new::{base::Base, prelude::*};
+    ///
+    /// #[derive(PartialEq, serde::Deserialize)]
+    /// pub enum ValidKinds {
+    ///     Video,
+    ///     Image,
+    /// }
+    ///
+    /// let video: Base<ValidKinds> = serde_json::from_str(r#"{"type":"Video"}"#)?;
+    ///
+    /// assert!(video.is_kind(&ValidKinds::Video));
+    /// # Ok(())
+    /// # }
+    /// ```
+    fn is_kind(&self, kind: &Kind) -> bool
+    where
+        Kind: PartialEq,
+    {
+        self.kind() == Some(kind)
+    }
+
     /// Set the kind for the current object
     ///
     /// This overwrites the contents of kind