refactor: Add requireSameFeedId method to FeedScopedId

Author: t2gran

application/src/main/java/org/opentripplanner/transit/model/framework/FeedScopedId.java

@@ -90,6 +90,14 @@ public static boolean isValidString(@Nullable String value) throws IllegalArgume
     return value != null && value.indexOf(ID_SEPARATOR) > -1;
   }
 
+  public void requireSameFeedId(FeedScopedId other) {
+    if (!feedId.equals(other.feedId)) {
+      throw new IllegalArgumentException(
+        "FeedIds does not match: '" + feedId + "' != '" + other.feedId + "'"
+      );
+    }
+  }
+
   /**
    * Concatenate feedId and id into a string.
    */

application/src/test/java/org/opentripplanner/transit/model/framework/FeedScopedIdTest.java

@@ -54,6 +54,14 @@ void parseList() {
     );
   }
 
+  @Test
+  void requireSameFeedId() {
+    var ex = assertThrows(IllegalArgumentException.class, () ->
+      new FeedScopedId("F", "1").requireSameFeedId(new FeedScopedId("E", "1"))
+    );
+    assertEquals("FeedIds does not match: 'F' != 'E'", ex.getMessage());
+  }
+
   @Test
   void throwWhenParsingNull() {
     var input = new ArrayList<String>();