
  -spec is_record(Term, RecordTag, Size) -> boolean()
                     when
                         Term :: term(),
                         RecordTag :: atom(),
                         Size :: non_neg_integer().

  RecordTag must be an atom.

  Returns true if Term is a tuple, its first element is 
  RecordTag, and its size is Size. Otherwise returns false.

  Allowed in guard tests if RecordTag is a literal atom and Size
  is a literal integer.

  Note:
    This BIF is documented for completeness. Usually is_record/2
    is to be used.
