     }
 }
 
-public class BinaryTarget: Target {
+public final class BinaryTarget: Target {
 
     /// The original source of the binary artifact.
     public enum ArtifactSource: Equatable, Codable {

    }
}

public class ClangTarget: Target {

    /// The default public include directory component.
    public static let defaultPublicHeadersComponent = "include"

    }
}

public final class SystemLibraryTarget: Target {

    /// The name of pkgConfig file, if any.
    public let pkgConfig: String?
