only use keras_array if it's not a python object for tfdatasets case

Author: dfalbel

R/layer-methods.R

@@ -169,7 +169,8 @@ as_node_index <- function(node_index) {
 #' @export
 adapt <- function(object, data, reset_state = NULL) {
 
-  data <- keras_array(data)
+  if (!inherits(data, "python.builtin.object"))
+    data <- keras_array(data)
 
   # layers can implement adapt with different default reset_state
   if (is.null(reset_state))