code: public VfsInputStream readFile(@NotNull final Transaction txn, @NotNull final File file) {
          return new VfsInputStream(this, txn, file.getDescriptor());
      }
docs: Returns {@linkplain InputStream} to read contents of the specified file from the beginning.
  
  @param txn  {@linkplain Transaction} instance
  @param file {@linkplain File} instance
  @return {@linkplain java.io.InputStream} to read contents of the specified file from the beginning
  @see #readFile(Transaction, long)
  @see #readFile(Transaction, File, long)
  @see #writeFile(Transaction, File)
  @see #writeFile(Transaction, long)
  @see #writeFile(Transaction, File, long)
  @see #writeFile(Transaction, long, long)
  @see #appendFile(Transaction, File)
  @see #touchFile(Transaction, File)