diff --git a/source/src/main/java/one/nem/lacerta/source/file/DocFiles.java b/source/src/main/java/one/nem/lacerta/source/file/DocFiles.java
new file mode 100644
index 00000000..522cb2bb
--- /dev/null
+++ b/source/src/main/java/one/nem/lacerta/source/file/DocFiles.java
@@ -0,0 +1,4 @@
+package one.nem.lacerta.source.file;
+
+public interface DocFiles {
+}
diff --git a/source/src/main/java/one/nem/lacerta/source/file/factory/placeholder b/source/src/main/java/one/nem/lacerta/source/file/factory/placeholder
new file mode 100644
index 00000000..e69de29b
diff --git a/source/src/main/java/one/nem/lacerta/source/file/impl/placeholder b/source/src/main/java/one/nem/lacerta/source/file/impl/placeholder
new file mode 100644
index 00000000..e69de29b
diff --git a/source/src/main/java/one/nem/lacerta/source/file/module/placeholder b/source/src/main/java/one/nem/lacerta/source/file/module/placeholder
new file mode 100644
index 00000000..e69de29b