API IsFishingLoot

__NOTOC__
This function is only for determining if the loot window is related to fishing.
===Returns===
:;isTrue: - is it true
==Example==
This will identify that the loot window should display the fish graphic, then play the sound and update the image.
 if( IsFishingLoot() ) then
 PlaySound("FISHING REEL IN");
 LootFramePortraitOverlay:SetTexture("Interface\\LootFrame\\FishingLoot-Icon");
 end