text: create r scalar script dob_1i_1o(x double) emits(y double)
  as
  run <- function(ctx) {
    ctx$emit(ctx$x)
    ctx$emit(ctx$x)
  }
  /
  create r scalar script line_1i_1o(x double) emits(y double)
  as
  run <- function(ctx) {
    ctx$emit(ctx$x)
  }
  /
  create r scalar script line_1i_2o(x double) emits(y double, z double)
  as
  run <- function(ctx) {
    ctx$emit(ctx$x, ctx$x)
  }
  /
  create r scalar script line_2i_1o(x double, y double) emits(z double)
  as
  run <- function(ctx) {
    ctx$emit(ctx$x + ctx$y)
  }
  /
  create r scalar script line_3i_2o(x double, y double, z double) emits(z1 double, z2 double)
  as
  run <- function(ctx) {
    ctx$emit(ctx$x + ctx$y, 3000)
  }
  /
  