move internal methods from public api

GitOrigin-RevId: e20016b79d21a526704c731ba33e6977f3fcb5e4

platform/indexing-impl/src/com/intellij/psi/stubs/SerializationManager.java

@@ -19,15 +19,9 @@ public abstract class SerializationManager {
    */
   @ApiStatus.Internal
   public void registerSerializer(ObjectStubSerializer<?, ? extends Stub> serializer) {
-    registerSerializer(serializer.getExternalId(), () -> serializer);
+    throw new UnsupportedOperationException();
   }
 
-  /**
-   * Use {@link StubElementTypeHolderEP} to register stub serializer instead of manual registration.
-   */
-  @ApiStatus.Internal
-  protected abstract void registerSerializer(@NotNull String externalId, Supplier<ObjectStubSerializer<?, ? extends Stub>> lazySerializer);
-
   @Contract("null -> null")
   public abstract @Nullable String internString(@Nullable String string);
 }

platform/indexing-impl/src/com/intellij/psi/stubs/SerializationManagerImpl.java

@@ -140,6 +140,11 @@ public final class SerializationManagerImpl extends SerializationManagerEx imple
     }
   }
 
+  @Override
+  public void registerSerializer(ObjectStubSerializer<?, ? extends Stub> serializer) {
+    registerSerializer(serializer.getExternalId(), () -> serializer);
+  }
+
   @Override
   public String internString(String string) {
     return myStubSerializationHelper.intern(string);
@@ -181,8 +186,7 @@ public final class SerializationManagerImpl extends SerializationManagerEx imple
     }
   }
 
-  @Override
-  protected void registerSerializer(@NotNull String externalId, Supplier<ObjectStubSerializer<?, ? extends Stub>> lazySerializer) {
+  private void registerSerializer(@NotNull String externalId, @NotNull Supplier<ObjectStubSerializer<?, ? extends Stub>> lazySerializer) {
     try {
       myStubSerializationHelper.assignId(lazySerializer, externalId);
     }