Method binding

crates/csskit_derives/src/parse.rs:164–171

(&self)

	}

	fn binding(&self) -> TokenStream {
		let Field { var, ty, .. } = self;
		if ty.is_option() {
			quote! { let mut #var: #ty = None; }
		} else {
			quote! { let mut #var: Option<#ty> = None; }
		}
	}

	fn none_check(&self) -> TokenStream {
		let v = &self.var;