API IsSpellClassOrSpec

Returns whether a given spell is specific to a specialization and/or class.
 spec, class = IsSpellClassOrSpec(spellName or spellIndex, bookType)
==Arguments==
:;spellname: - name of the spell currently known by the player.
or
:;spellIndex: - spell book slot index, ascending from 1.
:;bookType: - spell book type, e.g. BOOKTYPE_SPELL ("spell") for player's spell book.
==Returns==
:;spec: - name of the specialization the spell is exclusive to, nil if not a specialization-granted spell.
:; class: - name of the class the spell is exclusive to, nil if not a class ability.
==Patch changes==