Add a very silly table

crates/nu-protocol/src/value/mod.rs

@@ -288,6 +288,13 @@ impl Value {
     pub fn is_true(&self) -> bool {
         matches!(self, Value::Bool { val: true, .. })
     }
+
+    pub fn columns(&self) -> Vec<String> {
+        match self {
+            Value::Record { cols, .. } => cols.clone(),
+            _ => vec![],
+        }
+    }
 }
 
 impl PartialEq for Value {