test: add test for entity new and with_attribute constructor functions

01.workspace/heave/src/tst/entity_new.rs

@@ -0,0 +1,10 @@
+#[cfg(test)]
+mod tests {
+    use crate::*;
+    #[test]
+    pub fn check_001() {
+        let entity = Entity::new("class");
+        assert_eq!(entity.class, String::from("class"));
+        assert_eq!(entity.attributes.len(), 0);
+    }
+}

01.workspace/heave/src/tst/entity_with_attribute.rs

@@ -0,0 +1,15 @@
+#[cfg(test)]
+mod tests {
+    use crate::*;
+    #[test]
+    pub fn check_001() {
+        let entity = Entity::new("class").with_attribute("a001", 0u64);
+        assert_eq!(
+            entity.attributes.get("a001"),
+            Some(&Attribute {
+                id: "a001".to_string(),
+                value: Value::UnsignedInt(0)
+            })
+        );
+    }
+}

01.workspace/heave/src/tst/mod.rs

@@ -1 +1,2 @@
-
+pub mod entity_new;
+pub mod entity_with_attribute;