pub trait IsVec: Debug {
// Required methods
fn into_any(self: Box<Self>) -> Box<dyn Any>;
fn as_any(&self) -> &dyn Any;
fn box_clone(&self) -> Box<dyn IsVec>;
fn eq(&self, other: &dyn Any) -> bool;
fn subset(&self, indicator: &Vec<bool>) -> Box<dyn IsVec>;
}