Move internal modules to “internal” folder.

.internal/baseAt.js

@@ -0,0 +1,23 @@
+import get from './get.js';
+
+/**
+ * The base implementation of `at` without support for individual paths.
+ *
+ * @private
+ * @param {Object} object The object to iterate over.
+ * @param {string[]} paths The property paths to pick.
+ * @returns {Array} Returns the picked elements.
+ */
+function baseAt(object, paths) {
+  let index = -1;
+  const length = paths.length;
+  const result = Array(length);
+  const skip = object == null;
+
+  while (++index < length) {
+    result[index] = skip ? undefined : get(object, paths[index]);
+  }
+  return result;
+}
+
+export default baseAt;