does the PSD importer come with source code ?

PSD importer has a big issue... if you use the same sprite multiple times ( multiple layers) in photoshop file, for a scene prop. or character, the imported sprite atlas will duplicate the sprite N times on the texture atlas also, instead of recognizing that it is the same sprite used N times. I'd like to try to fix this in the source code.... if possible. or are there any existing solutions already ?