refactor stack. Add details to example tests.

__mocks__/expo-file-system.js

@@ -0,0 +1,10 @@
+// __mocks__/expo-file-system.js
+export const File = {
+  // Define the properties and methods you need for your tests
+  uri: 'file:///path/to/file',
+};
+
+export const Paths = {
+  // Define the paths you need for your tests
+  DOCUMENTS_DIRECTORY: '/path/to/documents',
+};