class RDoc::Generator::API

def generate_class_tree_level(classes, visited = {})
  # Only process core extensions on the first visit and remove
  # Active Storage duplicated classes that are at the top level
  # since they aren't nested under a definition of the `ActiveStorage` module.
  if visited.empty?
    classes = classes.reject { |klass| active_storage?(klass) }
    core_exts = classes.extract! { |klass| core_extension?(klass) }
    super.unshift([ "Core extensions", "", "", build_core_ext_subtree(core_exts, visited) ])
  else
    super
  end
end