Describe the bug
The following method declaration is only usable by graphql.schema.SchemaTraverser since the second arguments type is a private static inner class:
public TraverserResult depthFirst(final Traverser<GraphQLSchemaElement> traverser, final TraverserDelegateVisitor traverserDelegateVisitor, Collection<? extends GraphQLSchemaElement> roots);
I suspect that the signature should have been either private, or:
public TraverserResult depthFirst(final Traverser<GraphQLSchemaElement> traverser, final TraverserVisitor<GraphQLSchemaElement> traverserVisitor, Collection<? extends GraphQLSchemaElement> roots);