t() :: %ExDoc.FunctionNode{
  annotations: list(),
  arity: non_neg_integer(),
  defaults: non_neg_integer(),
  deprecated: nil | String.t(),
  doc: term(),
  doc_line: non_neg_integer(),
  group: nil | String.t(),
  id: nil | String.t(),
  name: nil | String.t(),
  rendered_doc: nil | String.t(),
  signature: nil | String.t(),
  source_path: nil | String.t(),
  source_url: nil | String.t(),
  specs: list(),
  type: nil | String.t()
}