class SchemaWalker {

  @SuppressWarnings("unchecked")
  public static <S, F> S visit(final Schema schema, final Visitor<S, F> visitor) {
    final BiFunction<Visitor<?, ?>, Schema, Object> handler = HANDLER.get(schema.type());
    if (handler == null) {
      throw new UnsupportedOperationException("Unsupported schema type: " + schema.type());
    }

    return (S) handler.apply(visitor, schema);
  }

  private  SchemaWalker();

}