#[derive(Debug)]
pub struct Rectangle {
    length: u32,
    width: u32
}

impl Rectangle {
    pub fn can_hold(&self, other: &Rectangle) -> bool {
        self.length > other.length && self.width > other.width
    }
}

#[cfg(test)]
mod tests {
    #[test]
    fn it_works() {
    }

    #[test]
    fn it_panics() {
        panic!("Make this test fail!");
    }
}

#[cfg(test)]
mod tests {
    #[test]
    fn it_works() {
    }
}

--- 
+++ 
@@ -1,6 +1,23 @@
+#[derive(Debug)]
+pub struct Rectangle {
+    length: u32,
+    width: u32
+}
+
+impl Rectangle {
+    pub fn can_hold(&self, other: &Rectangle) -> bool {
+        self.length > other.length && self.width > other.width
+    }
+}
+
 #[cfg(test)]
 mod tests {
     #[test]
     fn it_works() {
     }
+
+    #[test]
+    fn it_panics() {
+        panic!("Make this test fail!");
+    }
 }
Add struct and method for testing
