setGeneric("fcs_to_img", function(files, ...) standardGeneric("fcs_to_img"))
setGeneric("img_sub", function(files, ...) standardGeneric("img_sub"))
setGeneric("calculate_overlaps_xor", function(subsets, ...) standardGeneric("calculate_overlaps_xor"))
setGeneric("plot_nmds", function(x, y, ...) standardGeneric("plot_nmds"))