diff --git a/01.workspace/heave/src/tst/intended_use.rs b/01.workspace/heave/src/tst/intended_use.rs
index 77c1b32..5b6f313 100644
--- a/01.workspace/heave/src/tst/intended_use.rs
+++ b/01.workspace/heave/src/tst/intended_use.rs
@@ -1,219 +1,71 @@
 #[cfg(test)]
 mod tests {
     use crate::*;
-    #[derive(Debug, Clone, PartialEq)]
+    #[derive(Clone, Debug, PartialEq)]
     struct Product {
-        pub id: String,
-        pub name: String,
-        pub price: u64,
+        id: String,
+        name: String,
+        model: Option<String>,
+        price: u64,
+        in_stock: bool,
     }
     impl EAV for Product {
         fn class() -> &'static str {
             "product"
         }
     }
-    impl From<Product> for Entity {
-        fn from(value: Product) -> Entity {
-            Entity::new::<Product>()
-                .with_id(&value.id)
-                .with_attribute("name", value.name)
-                .with_attribute("price", value.price)
-        }
-    }
     impl From<Entity> for Product {
         fn from(entity: Entity) -> Self {
             Product {
                 id: entity.id.clone(),
                 name: entity.unwrap("name"),
-                price: entity.unwrap("price"),
+                model: entity.unwrap_opt("model"),
+                price: entity.unwrap_or("price", 0),
+                in_stock: entity.unwrap("in_stock"),
             }
         }
     }
-    #[test]
-    fn check_001() {
-        // Demonstrates the costruction of a new entity instance
-        let _product = Entity::new::<Product>()
-            .with_attribute("name", "laptop")
-            .with_attribute("price", 200000u64)
-            .with_attribute("discount", 2.5f64)
-            .with_attribute("in_stock", true);
+    impl From<Product> for Entity {
+        fn from(value: Product) -> Self {
+            let mut entity = Entity::new::<Product>()
+                .with_id(&value.id)
+                .with_attribute("name", value.name)
+                .with_attribute("price", value.price)
+                .with_attribute("in_stock", value.in_stock);
+            if let Some(model) = value.model {
+                entity.set("model", model);
+            }
+            entity
+        }
     }
     #[test]
-    fn check_002() {
-        // Demonstrate attribute value reading
-        let product = Entity::new::<Product>()
-            .with_attribute("name", "laptop")
-            .with_attribute("price", 200000u64);
-        let name = product.value_of("name");
-        let price = product.value_of("price");
-        assert_eq!(name, Some(&Value::Text(String::from("laptop"))));
-        assert_eq!(price, Some(&Value::UnsignedInt(200000)));
-    }
-    #[test]
-    fn check_003() {
-        // Demonstrate attribute value setting
-        let mut product = Entity::new::<Product>();
-        // new product
-        product.set("price", 200000u64);
-        // set price
-        let price = product.value_of("price");
-        assert_eq!(price, Some(&Value::UnsignedInt(200000)));
-        // set in stock
-        product.set("in_stock", true);
-        let in_stock = product.value_of("in_stock");
-        assert_eq!(in_stock, Some(&Value::Bool(true)));
-        // set in stock again
-        let prev_in_stock = product.set("in_stock", false);
-        let in_stock = product.value_of("in_stock");
-        assert_eq!(prev_in_stock, Some(Value::Bool(true)));
-        assert_eq!(in_stock, Some(&Value::Bool(false)));
-    }
-    #[test]
-    fn check_004() {
-        // // new entities
-        // let product = Entity::new::<Product>();
-        // let category = Entity::new::<Category>();
-        // // id clones for testing purposes
-        // let product_id = product.id.clone();
-        // let category_id = category.id.clone();
-        // // new relation as entity
-        // let product_has_category = Entity::new("product_has_category")
-        // .with_attribute("product", product)
-        // .with_attribute("category", category);
-        // assert_eq!(
-        // product_has_category.value_of("product"),
-        // Some(&Value::Text(product_id))
-        // );
-        // assert_eq!(
-        // product_has_category.value_of("category"),
-        // Some(&Value::Text(category_id))
-        // );
-    }
-    #[test]
-    fn check_005() {
-        // let tag = Entity::new("tag").with_attribute("label", "new");
-        // let tag_id = tag.id.clone();
-        // let entity = Entity::new("product")
-        // .with_attribute("name", "laptop")
-        // .with_attribute("price", 200000u64)
-        // .with_attribute("delta", -50i64)
-        // .with_attribute("in_stock", true)
-        // .with_attribute("discount", 5.2f64)
-        // .with_attribute("tag", tag);
-        // let name: String = entity.unwrap("name");
-        // let price: u64 = entity.unwrap("price");
-        // let delta: i64 = entity.unwrap("delta");
-        // let in_stock: bool = entity.unwrap("in_stock");
-        // let discount: f64 = entity.unwrap("discount");
-        // let tag: Entity = entity.unwrap("tag");
-        // assert_eq!(name, "laptop".to_string());
-        // assert_eq!(price, 200000u64);
-        // assert_eq!(delta, -50i64);
-        // assert!(in_stock);
-        // assert_eq!(discount, 5.2f64);
-        // assert_eq!(tag.id, tag_id);
-    }
-    #[test]
-    fn check_006() {
-        let product = Product {
-            id: "abcdef".to_string(),
-            name: "laptop".to_string(),
-            price: 200000u64,
-        };
-        let expected_product = product.clone();
-        let entity: Entity = product.into();
-        let converted_product = Product::from(entity);
-        assert_eq!(expected_product, converted_product);
-    }
-    #[test]
-    fn check_007() {
-        let mut catalog = Catalog::new("");
-        let product = Product {
-            id: short_uuid::short!().to_string(),
-            name: "laptop".to_string(),
-            price: 200000u64,
-        };
-        catalog.insert(product);
-    }
-    #[test]
-    fn check_008() {
-        let mut catalog = Catalog::new("");
-        let product01 = Product {
-            id: short_uuid::short!().to_string(),
-            name: "laptop".to_string(),
-            price: 200000u64,
-        };
-        let product02 = Product {
-            id: short_uuid::short!().to_string(),
-            name: "desktop".to_string(),
-            price: 150000u64,
-        };
-        let products = vec![product01, product02];
-        catalog.insert_many(products);
-    }
-    #[test]
-    fn check_009() {
-        let mut catalog = Catalog::new("");
-        let product = Product {
-            id: short_uuid::short!().to_string(),
-            name: "laptop".to_string(),
-            price: 200000u64,
-        };
-        let expected_product = product.clone();
-        catalog.insert(product);
-        let read_product: Product = catalog.get(&expected_product.id).unwrap();
-        assert_eq!(read_product, expected_product);
-    }
-    #[test]
-    fn check_010() {
-        // // demonstrates load entity by id
-        // let tempfile = tempfile::NamedTempFile::new().unwrap();
-        // let path = tempfile.path().to_str().unwrap();
-        // // insert a new entity
-        // let mut catalog = Catalog::new(path);
-        // catalog.init();
-        // let entity = Entity::new("test")
-        // .with_attribute("int", Value::SignedInt(50))
-        // .with_attribute("string", Value::Text("text".to_string()));
-        // let id = entity.id.clone();
-        // let expected_entity = Entity {
-        // state: EntityState::Loaded,
-        // ..entity.clone()
-        // };
-        // catalog.insert(entity);
-        // catalog.persist();
-        // // read the entity in a new catalog
-        // let mut catalog = Catalog::new(path);
-        // catalog.load_by_id(&id);
-        // let entity: Entity = catalog.get(&id).unwrap();
-        // assert_eq!(expected_entity, entity,);
-    }
-    #[test]
-    fn check_011() {
-        // demonstrate load by class
+    /// # Example 1
+    ///
+    /// - How to create a new empty catalog
+    /// - How to insert a new entity
+    /// - How to read the entity by id
+    fn scenario_001() {
+        // create a new named temp file
         let tempfile = tempfile::NamedTempFile::new().unwrap();
         let path = tempfile.path();
-        let mut catalog = Catalog::new(path.to_str().unwrap());
-        catalog.init();
-        let product_01 = Product {
+        let path = path.to_str().unwrap();
+        // initialize a new empty catalog given an existing path
+        let mut catalog = Catalog::new(path);
+        // create a new object
+        let product = Product {
             id: short_uuid::short!().to_string(),
-            name: "laptop".to_string(),
-            price: 200000u64,
+            name: String::from("PenguinX Laptop"),
+            model: None,
+            price: 135000,
+            in_stock: true,
         };
-        let product_02 = Product {
-            id: short_uuid::short!().to_string(),
-            name: "desktop".to_string(),
-            price: 300000u64,
-        };
-        let expected_value_01 = product_01.clone();
-        catalog.insert(product_01);
-        catalog.insert(product_02);
-        catalog.persist();
-        // new empty catalog
-        let mut catalog = Catalog::new(path.to_str().unwrap());
-        catalog.load_by_class::<Product>();
-        assert_eq!(catalog.items.len(), 2);
-        let loaded_value_01: Product = catalog.get(&expected_value_01.id).unwrap();
-        assert_eq!(loaded_value_01, expected_value_01);
+        // save some info for late comparison
+        let original_product = product.clone();
+        // insert the new object into catalog consuming it
+        catalog.insert(product);
+        // read value from catalog using the original key
+        let read_product = catalog.get::<Product>(&original_product.id).unwrap();
+        // assert equality between original and read
+        assert_eq!(original_product, read_product);
     }
 }