Allow to evolve l.d.Attributes while maintaining bin compat

modules/lm-coursier/src/main/scala/lmcoursier/definitions/Attributes.scala

@@ -1,6 +1,35 @@
 package lmcoursier.definitions
 
-final case class Attributes(
-  `type`: Type,
-  classifier: Classifier
-)
+final class Attributes private (
+  val `type`: Type,
+  val classifier: Classifier
+) {
+
+  override def equals(obj: Any): Boolean =
+    obj match {
+      case other: Attributes =>
+        `type` == other.`type` && classifier == other.classifier
+      case _ => false
+    }
+  override def hashCode(): Int =
+    37 * (37 * (37 * (17 + "lmcoursier.definitions.Attributes".##) + `type`.##) + classifier.##)
+  override def toString: String =
+    s"Attributes(${`type`}, $classifier)"
+
+  private def copy(
+    `type`: Type = `type`,
+    classifier: Classifier = classifier
+  ): Attributes =
+    new Attributes(`type`, classifier)
+
+  def withType(`type`: Type): Attributes =
+    copy(`type` = `type`)
+  def withClassifier(classifier: Classifier): Attributes =
+    copy(classifier = classifier)
+
+}
+
+object Attributes {
+  def apply(`type`: Type, classifier: Classifier): Attributes =
+    new Attributes(`type`, classifier)
+}