def METHOD_NAME(package_name, file_path):
    absolute_file_path = ''
    if package_name:
        package_path = get_package_share_directory(package_name)
        absolute_file_path = os.path.join(package_path, file_path)
    else:
        absolute_file_path = file_path
    if not os.path.isfile(absolute_file_path):
        print('File "%s" was not found'%(absolute_file_path))
        sys.exit(-1)
    try:
        with open(absolute_file_path, "r") as file:
            return file.read()
    except EnvironmentError:  # parent of IOError, OSError *and* WindowsError where available
        return None