Move internal modules to “internal” folder.

.internal/baseSampleSize.js

@@ -0,0 +1,18 @@
+import baseClamp from './.internal/baseClamp.js';
+import shuffleSelf from './.internal/shuffleSelf.js';
+import values from './values.js';
+
+/**
+ * The base implementation of `sampleSize` without param guards.
+ *
+ * @private
+ * @param {Array|Object} collection The collection to sample.
+ * @param {number} n The number of elements to sample.
+ * @returns {Array} Returns the random elements.
+ */
+function baseSampleSize(collection, n) {
+  const array = values(collection);
+  return shuffleSelf(array, baseClamp(n, 0, array.length));
+}
+
+export default baseSampleSize;