## S3 method for class 'xts'
as.data.table(x, keep.rownames = TRUE, key=NULL, ...)

if (requireNamespace("xts", quietly = TRUE)) {
  data(sample_matrix, package = "xts")
  sample.xts <- xts::as.xts(sample_matrix) # xts might not be attached on search path
  # print head of xts
  print(head(sample.xts))
  # print data.table
  print(as.data.table(sample.xts))
}