def goto_line(line_num):
    """To go to a certain line.

    This function uses the ``G`` command to move the cursor to
    the beginning of a certain line.

    Usage:

    `In a config file:`

    .. code-block:: yaml

      - goto_line: 5

    `Using the API:`

    .. code-block:: python

      ezvi.tools.goto_line(5)

    :type line_num: int
    :param line_num: The number of the line to move the cursor to.

    :rtype: str
    :return: A line number appended with ``G``.
    """

    to_write = str(line_num) + "G"

    return to_write