message: simply 'if' block
diff: @@ -389,11 +389,9 @@ impl Dependency {
  }
  pub fn map_source(mut self, to_replace: SourceId, replace_with: SourceId) -> Dependency {
  - if self.source_id() != to_replace {
  - self
  - } else {
  + if self.source_id() == to_replace {
  self.set_source_id(replace_with);
  - self
  }
  + self
  }
  }
  