Initial implementations

src/main/kotlin/filesystem/FSCreator.kt

@@ -1,9 +1,13 @@
 package filesystem
 
+import java.nio.file.FileAlreadyExistsException
+import java.nio.file.FileSystemException
 import java.nio.file.Files
 import java.nio.file.Path
 
 class FSCreator {
+    // Create entry, leaving existing folders' contents, but overwriting existing files.
+    @Throws(FileSystemException::class)
     fun create(entryToCreate: FSEntry, destination: String) {
         val queue = ArrayDeque<Pair<FSEntry, Path>>()
         queue.add(entryToCreate to Path.of(destination))
@@ -17,8 +21,9 @@ class FSCreator {
                     is FSFolder -> Files.createDirectory(path)
                 }
             } catch (_: FileAlreadyExistsException) {} // Allow files/folders to already exist.
-            if (entry is FSFolder) {
-                queue.addAll(entry.entries.map { it to path })
+            when (entry) {
+                is FSFile -> Files.write(path, entry.content.toByteArray())
+                is FSFolder -> queue.addAll(entry.entries.map { it to path })
             }
         }
     }