Statistical Programming with R

The objective of this question is to give practice with various syntax to work with lists and understand their
use and limitations.
Consider the following command:
simple_list <- list("vector" = 1:10, "matrix" = matrix(6:1, nrow = 3, ncol = 2))

Add a component to simple_list that contains the NULL object. Verify that length(simple_list) == 3 returns TRUE.