Method error

crates/derive-impl/src/error.rs:78–85

(text: T)

impl Diagnostic {
    pub fn error<T: Into<String>>(text: T) -> Self {
        Self {
            inner: Repr::Single {
                text: text.into(),
                span: None,
            },
        }
    }

    pub(crate) fn spans_error<T: Into<String>>(spans: (Span, Span), text: T) -> Self {
        Self {