Plot density of several feature tyopes across the genome

featureDensity(
  feature_file1 = system.file("extdata", "g4_positions.txt", package = "svBreaks"),
  feature1 = "G4",
  feature_file2 = NA,
  feature2 = NA,
  feature_file3 = NA,
  feature3 = NA,
  write = TRUE,
  chroms = c("2L", "2R", "3L", "3R", "X")
)