diff --git a/DESCRIPTION b/DESCRIPTION
index 5ebae5a..68a9f55 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -14,7 +14,8 @@ Roxygen: list(markdown = TRUE)
 RoxygenNote: 7.3.2.9000
 Depends: R (>= 4.2.0)
 Imports:
-    R6
+    R6,
+    S7
 Suggests:
     testthat (>= 3.0.0)
 Config/testthat/edition: 3
diff --git a/NAMESPACE b/NAMESPACE
index 691e1ee..c0d6c6d 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -2,7 +2,9 @@
 
 export(LRUCache)
 export(get_dims)
+export(list_of)
 export(seq_along0)
 export(seq_len0)
 importFrom(R6,R6Class)
+importFrom(utils,getFromNamespace)
 importFrom(utils,hashtab)
diff --git a/R/list_of.R b/R/list_of.R
index 5fc2584..04f67de 100644
--- a/R/list_of.R
+++ b/R/list_of.R
@@ -1,73 +1,73 @@
-## copied from: https://github.com/lawremi/wizrd/blob/main/R/utils.R
-#
-##' @title Create a list property
-##' @description
-##' Create a list property.
-##' @param class The class of the list.
-##' @param ... The properties of the list.
-##' @export
-#list_of <- function(class, ...) {
-#  new_list_property(of = class, ...)
-#}
-#
-#new_list_property <- function(
-#  ...,
-#  validator = NULL,
-#  default = if (isTRUE(named)) {
-#    quote(setNames(list(), character()))
-#  } else {
-#    quote(list())
-#  },
-#  of = S7::class_any,
-#  named = NA,
-#  min_length = 0L,
-#  max_length = Inf
-#) {
-#  prop <- S7::new_property(
-#    S7::class_list,
-#    ...,
-#    validator = function(value) {
-#      c(
-#        if (
-#          !identical(of, S7::class_any) &&
-#            !all(vapply(value, S7:::class_inherits, logical(1L), of))
-#        ) {
-#          paste("must only contain elements of class", S7:::class_desc(of))
-#        },
-#        if (!is.null(of_validator)) {
-#          msgs <- unlist(lapply(value, of_validator))
-#          if (length(msgs) > 0L) {
-#            paste(
-#              "element(s) failed validation:",
-#              paste0("'", unique(msgs), "'", collapse = ", ")
-#            )
-#          }
-#        },
-#        if (isTRUE(named) && is.null(names(value))) {
-#          "must have names"
-#        },
-#        if (identical(named, FALSE) && !is.null(names(value))) {
-#          "must not have names"
-#        },
-#        if (length(value) < min_length || length(value) > max_length) {
-#          paste0("must have length in [", min_length, ", ", max_length, "]")
-#        },
-#        if (!is.null(validator)) {
-#          validator(value)
-#        }
-#      )
-#    },
-#    default = default
-#  )
-#  prop$of <- of
-#  if (inherits(of, "S7_property")) {
-#    of_validator <- of$validator
-#    of <- of$class
-#  } else {
-#    of_validator <- NULL
-#  }
-#  prop$named <- named
-#  class(prop) <- c("list_S7_property", class(prop))
-#  prop
-#}
-#
+# copied from: https://github.com/lawremi/wizrd/blob/main/R/utils.R
+
+#' @title Create a list property
+#' @description
+#' Create a list property.
+#' @param class The class of the list.
+#' @param ... The properties of the list.
+#' @export
+list_of <- function(class, ...) {
+  new_list_property(of = class, ...)
+}
+
+new_list_property <- function(
+  ...,
+  validator = NULL,
+  default = if (isTRUE(named)) {
+    quote(setNames(list(), character()))
+  } else {
+    quote(list())
+  },
+  of = S7::class_any,
+  named = NA,
+  min_length = 0L,
+  max_length = Inf
+) {
+  prop <- S7::new_property(
+    S7::class_list,
+    ...,
+    validator = function(value) {
+      c(
+        if (
+          !identical(of, S7::class_any) &&
+            !all(vapply(value, getFromNamespace("class_inherits", "S7"), logical(1L), of))
+        ) {
+          paste("must only contain elements of class", getFromNamespace("class_desc", "S7")(of))
+        },
+        if (!is.null(of_validator)) {
+          msgs <- unlist(lapply(value, of_validator))
+          if (length(msgs) > 0L) {
+            paste(
+              "element(s) failed validation:",
+              paste0("'", unique(msgs), "'", collapse = ", ")
+            )
+          }
+        },
+        if (isTRUE(named) && is.null(names(value))) {
+          "must have names"
+        },
+        if (identical(named, FALSE) && !is.null(names(value))) {
+          "must not have names"
+        },
+        if (length(value) < min_length || length(value) > max_length) {
+          paste0("must have length in [", min_length, ", ", max_length, "]")
+        },
+        if (!is.null(validator)) {
+          validator(value)
+        }
+      )
+    },
+    default = default
+  )
+  prop$of <- of
+  if (inherits(of, "S7_property")) {
+    of_validator <- of$validator
+    of <- of$class
+  } else {
+    of_validator <- NULL
+  }
+  prop$named <- named
+  class(prop) <- c("list_S7_property", class(prop))
+  prop
+}
+
diff --git a/R/xlamisc-package.R b/R/xlamisc-package.R
index 20fa85c..a05c1ea 100644
--- a/R/xlamisc-package.R
+++ b/R/xlamisc-package.R
@@ -1,2 +1,3 @@
 #' @importFrom R6 R6Class
+#' @importFrom utils getFromNamespace
 "_PACKAGE"
diff --git a/man/list_of.Rd b/man/list_of.Rd
new file mode 100644
index 0000000..3868ac0
--- /dev/null
+++ b/man/list_of.Rd
@@ -0,0 +1,16 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/list_of.R
+\name{list_of}
+\alias{list_of}
+\title{Create a list property}
+\usage{
+list_of(class, ...)
+}
+\arguments{
+\item{class}{The class of the list.}
+
+\item{...}{The properties of the list.}
+}
+\description{
+Create a list property.
+}