We thought it would be better to keep map logic in browse.js and data logic in this module. In browse.js we keep track of layers and then determine whether the dataManager needs to grab more data with what filters. If we kept this in here then we would have started to replicate a lot of the same code (e.g. if layerType === X, do something) in both files or move a lot of the map logic into dataManager where I think it makes less sense.