1. A computer implemented method for obtaining a repository of attributes sets, wherein attributes sets are statistically associated with a sequence template representing two or more context sequences, comprising: (a) obtaining a dataset of context sequences; (b) transforming each context sequence to a sequence template, thereby obtaining a dataset of sequence templates; (c) clustering said dataset of sequence templates into a plurality of clusters according to a distance formula; wherein at least one cluster is statistically associated with at least one attributes set; and (d) inserting into said repository each of said clusters and said attributes set which is statistically associated with said each of said clusters;