## ---- eval = FALSE-------------------------------------------------------
#  # instead of ellipsis would be specific arguments
#  method <- function(es,  rows = c(), columns = c(), replacea = "mean", ...) {
#      # Here may be some assertions
#  
#      # Data preparation
#      data <- prepareData(es, rows, columns, replacena)
#  
#      # Using method
#      res <- ...
#  
#      # Sending back the result as JSON:
#      return(jsonlite::toJSON(res))
#  
#      # Or as ProtoBuf
#      f <- tempfile(pattern = "pat", tmpdir = getwd(), fileext = ".bin")
#      writeBin(protolite::serialize_pb(res), f)
#      jsonlite::toJSON(f)
#  }