重複したメソッドを削除

source/src/main/java/one/nem/lacerta/source/file/FileManager.java

@@ -19,8 +19,6 @@ public interface FileManager {
     boolean isFile();
     boolean isWritable();
     boolean isReadable();
-    Document readXml();
-
     // Get current instance
     FileManager getCurrentInstance();
 

source/src/main/java/one/nem/lacerta/source/file/impl/FileManagerImpl.java

@@ -116,11 +116,6 @@ public class FileManagerImpl implements FileManager {
         }
     }
 
-    @Override
-    public Document readXml() {
-        return null;
-    }
-
     @Override
     public FileManager getCurrentInstance() {
         return this;