16. The computer program product of claim 15 , wherein each of the plurality of content items have an asset type selected from a group consisting of text and image.
16. The computer program product of claim 15 , wherein each of the plurality of content items have an asset type selected from a group consisting of text and image. 17. The computer program product of claim 16 , wherein the difference between the size of the slot of the candidate template and the size constraints of one or more of the plurality of content items is based on an aspect ratio of the slot in the candidate template and a minimum or a maximum aspect ratio of content items with having an asset type of image.