def fill_submit_wham(base_tpl, line_tpl, cur_step, use_part=False):
    """Fills the base template with one or more lines from the filled line
    template and returns the result.

    :param base_tpl: The base template to fill.  Expected to have a
        `{wham_block}` element.
    :param line_tpl: The line template to fill.  Expected to have one or
        more `{step}` elements.
    :param cur_step: The current step.
    :param use_part: Whether to add lines for each part of a split step.
    :return: The results of filling the template.
    """
    step_lines = []
    if use_part:
        for step_part in range(1, cur_step + 2):
            step_lines.append(line_tpl.format(step=cur_step, step_part=
                step_part))
    else:
        step_lines.append(line_tpl.format(step=cur_step))
    return base_tpl.format(wham_block=''.join(step_lines))
