@type t() :: %ExDoc.FunctionNode{
  annotations: [annotation()],
  arity: non_neg_integer(),
  defaults: [function_default()],
  deprecated: String.t() | nil,
  doc: ExDoc.DocAST.t() | nil,
  doc_line: non_neg_integer(),
  group: atom() | nil,
  id: String.t(),
  name: atom(),
  rendered_doc: String.t() | nil,
  signature: String.t(),
  source_path: String.t(),
  source_url: String.t() | nil,
  specs: [ExDoc.Language.spec_ast()],
  type: atom()
}