basic tests done, fixed children calculation problem

src/main.rs

@@ -5,18 +5,4 @@ mod node;
 #[cfg(test)]
 mod tests;
 
-fn main() {
-    let mut formula = Formula::new();
-    formula
-        .modify_tree()
-        .insert_node(Node::function(|inputs| inputs.iter().sum(), Some(2)), None);
-    if let Err(x) = formula
-        .modify_tree()
-        .go_down(0)
-        .add_node(Node::number(1f64))
-    {
-        println!("{x}");
-    }
-    formula.display_tree();
-    let results = formula.run(vec![0f64, 1f64, 2f64, 3f64, 4f64, 5f64]);
-}
+fn main() {}