@type t() :: %ProgramFacts.Fact.Branch{
  calls_by_clause: [ProgramFacts.Fact.BranchCall.t()],
  clauses: non_neg_integer(),
  function: ProgramFacts.Fact.FunctionID.t() | nil,
  kind: atom(),
  nested: [t()],
  state_action: atom() | nil
}