public JGitFileSystem get(String fsName) { Supplier<JGitFileSystem> memoizedSupplier = memoizedSuppliers.get(fsName); if (memoizedSupplier != null) { return new JGitFileSystemProxy(fsName, memoizedSupplier); } else if (fileSystemsSuppliers.get(fsName) != null) { Supplier<JGitFileSystem> newMemoizedSupplier = createMemoizedSupplier(fsName, fileSystemsSuppliers.get(fsName)); return new JGitFileSystemProxy(fsName, newMemoizedSupplier); } return null; }