Error in `gtable_add_grob(gt, grobs, t = positions$t, b = positions$b, 
    l = positions$l, r = positions$r, z = seq_along(grobs), clip = clip)`: `grobs` must be a single grob or a list of grobs, not a list.

test_that("plot_weights runs without error", {
expect_silent(plot_weights(output_obj, factor_num = "all", data = "omic.one", type = "scatter"))