message: remove extraneous import of Sign
diff: @@ -10,7 +10,7 @@ pub extern crate quickcheck;
  #[cfg(test)]
  #[cfg(feature = "quickcheck")]
  mod quickchecks {
  - use num_bigint::{BigInt, BigUint, Sign};
  + use num_bigint::{BigInt, BigUint};
  use num_traits::{Num, One, Pow, Zero};
  use quickcheck::TestResult;
  