move to another file

src/about_variables.rs

@@ -0,0 +1,20 @@
+#[allow(dead_code)]
+mod about_variables {
+    pub fn guess_this () -> i32 {
+        let one = 5;
+        let two = 7;
+        let three = 3;
+        let result = (one + two) / three;
+        return result;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::about_variables::*;
+
+    #[test]
+    fn test_complicated () {
+        assert_eq!(___, guess_this());
+    }
+}

src/lib.rs

@@ -1,20 +0,0 @@
-#[allow(dead_code)]
-mod about_variables {
-    pub fn guess_this () -> i32 {
-        let one = 5;
-        let two = 7;
-        let three = 3;
-        let result = (one + two) / three;
-        return result;
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::about_variables::*;
-
-    #[test]
-    fn test_complicated () {
-        assert_eq!(___, guess_this());
-    }
-}