use base64; use serde_json; error_chain! { errors { InvalidToken { description("invalid token") display("Invalid token") } InvalidSignature { description("invalid signature") display("Invalid signature") } WrongAlgorithmHeader { description("Wrong Algorithm Header") display("Wrong Algorithm Header") } } foreign_links { Base64(base64::Base64Error); Json(serde_json::Error); Utf8(::std::string::FromUtf8Error); } }