diff --git a/01.workspace/heave/src/lib.rs b/01.workspace/heave/src/lib.rs
index 89aee4f..e5e9007 100644
--- a/01.workspace/heave/src/lib.rs
+++ b/01.workspace/heave/src/lib.rs
@@ -8,9 +8,12 @@ mod trt;
 mod tst;
 
 pub use crate::str::attribute::O as Attribute;
+pub use crate::str::catalog::O as Catalog;
 pub use crate::str::entity::O as Entity;
 pub use crate::str::value::E as Value;
 pub use crate::trt::eav::T as EAV;
 pub use crate::trt::from_eav::T as FromEAV;
 pub use crate::trt::to_eav::T as ToEAV;
 pub use crate::trt::to_value::T as ToValue;
+
+pub mod sqlite {}
diff --git a/01.workspace/heave/src/str/catalog.rs b/01.workspace/heave/src/str/catalog.rs
new file mode 100644
index 0000000..4b9e628
--- /dev/null
+++ b/01.workspace/heave/src/str/catalog.rs
@@ -0,0 +1,31 @@
+use crate::*;
+
+#[derive(Debug, Default, PartialEq, Clone)]
+pub struct O {
+    path: String,
+    items: std::collections::HashMap<String, Entity>,
+}
+
+impl O {
+    pub fn new(path: &str) -> Self {
+        Self {
+            path: String::from(path),
+            ..O::default()
+        }
+    }
+    pub fn persist(&mut self, entity: &mut Entity) {
+        self.items.insert(entity.id.clone(), entity.clone());
+        entity.persisted = true;
+    }
+}
+
+// impl std::fmt::Display for O {
+// fn fmt(&self, _f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+// todo!();
+// }
+// }
+
+// #[cfg(test)]
+// mod unit_tests {
+// use super::*;
+// }
diff --git a/01.workspace/heave/src/str/entity.rs b/01.workspace/heave/src/str/entity.rs
index 3874934..6038eb5 100644
--- a/01.workspace/heave/src/str/entity.rs
+++ b/01.workspace/heave/src/str/entity.rs
@@ -59,10 +59,4 @@ impl O {
         let value = self.value_of(id).unwrap();
         T::from(value.clone())
     }
-    pub fn persist(&self) {
-        todo!()
-    }
-    pub fn load(_id: &str) -> Self {
-        todo!()
-    }
 }
diff --git a/01.workspace/heave/src/str/mod.rs b/01.workspace/heave/src/str/mod.rs
index dd1e5a1..d11628e 100644
--- a/01.workspace/heave/src/str/mod.rs
+++ b/01.workspace/heave/src/str/mod.rs
@@ -1,3 +1,4 @@
 pub mod attribute;
+pub mod catalog;
 pub mod entity;
 pub mod value;
diff --git a/01.workspace/heave/src/tst/intended_use.rs b/01.workspace/heave/src/tst/intended_use.rs
index 671a5ff..9c0c35f 100644
--- a/01.workspace/heave/src/tst/intended_use.rs
+++ b/01.workspace/heave/src/tst/intended_use.rs
@@ -122,4 +122,15 @@ mod tests {
         let converted_product = Product::from_eav(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,
+        };
+        let mut entity = product.to_eav();
+        catalog.persist(&mut entity);
+    }
 }