Find motifs overrepresented in a given set of genomic features. Computes the number of features
containing the motif (observed) and compares this to the total number of features containing the
motif (background) using the hypergeometric test.
A vector of features to test for enrichments over background
background
Either a vector of features to use as the background set,
or a number specify the number of features to randomly select as a background set.
If a number is provided, regions will be selected to match the sequence characteristics
of the query features. To match the sequence characteristics, these characteristics
must be stored in the feature metadata for the assay. This can be added using the
RegionStats function. If NULL, use all features in the assay.