EnrichStep-class        Base class of this package
GenBackground           Generate background regions and reset the size
                        of foreground regions
MotifsInRegions         Find motifs in all input sequence regions
PECA_TF_enrich          TF enrichment with PECA model
RegionConnectTargetGene
                        Connect regions with their target genes
TFsEnrichInRegions      Test each TF is enriched in regions or not
