message: Test and fix Timestamp::plus_seconds
diff: @@ -23,7 +23,7 @@ impl Timestamp {
  }
  pub fn plus_seconds(&self, addition: u64) -> Timestamp {
  - let nanos = self.0 + Uint64::from(addition);
  + let nanos = self.0 + Uint64::from(addition * 1_000_000_000);
  Timestamp(nanos)
  }
  }
  @@ -47,4 +47,12 @@ mod tests {
  let t = Timestamp::from_seconds(0);
  assert_eq!(t.0.u64(), 0);
  }
  +
  + #[test]
  + fn timestamp_plus_seconds() {
  + let sum = Timestamp::from_nanos(123).plus_seconds(42);
  + assert_eq!(sum.0.u64(), 42_000_000_123);
  + let sum = Timestamp::from_nanos(123).plus_seconds(0);
  + assert_eq!(sum.0.u64(), 123);
  + }
  }
  