private static void writeByteBufToFile(ByteBuf buffer, FileOutputStream outputFileStream) throws IOException {
    buffer.readBytes(outputFileStream, buffer.readableBytes());
  }
Writes the content of {@code buffer} into {@link ServerAdminToolConfig#dataOutputFilePath}.
@param buffer the {@link ByteBuf} whose content needs to be written.
@param outputFileStream the {@link FileOutputStream} to write to.
@throws IOException
ambry-tools/src/main/java/com/github/ambry/tools/admin/ServerAdminTool.java