pub fn push<T: Into<Sexp>>(&mut self, element: T) {
        match *self {
            Sexp::List(ref mut v) => v.push(element.into()),
            _ => panic!("Only use push on lists!"),
        }
    }
/// push an element in a list
push an element in a list
push an element in a list
pub fn push<T: Into<Sexp>>(&mut self, element: T) {
        match *self {
            Sexp::List(ref mut v) => v.push(element.into()),
            _ => panic!("Only use push on lists!"),
        }
    }
pub fn push < T : Into < Sexp > > ( & mut self , element : T ) { match * self { Sexp :: List ( ref mut v ) => v . push ( element . into ( ) ) , _ => panic ! ( " " ) , } }
push an element in a list
push an element in a list
&mut self
element
T