
  -spec erlang:external_size(Term, Options) -> non_neg_integer()
                                when
                                    Term :: term(),
                                    Options ::
                                        [{minor_version,
                                          Version :: non_neg_integer()}].

Since:
  OTP R14B04

  Calculates, without doing the encoding, the maximum byte size for
  a term encoded in the Erlang external term format. The following
  condition applies always:

    > Size1 = byte_size(term_to_binary(Term, Options)),
    > Size2 = erlang:external_size(Term, Options),
    > true = Size1 =< Size2.
    true

  Option {minor_version, Version} specifies how floats are
  encoded. For a detailed description, see term_to_binary/2.
