import textwrap


def _inject_in_docstring(docstring: str, text: str) -> str:
    """Inject a string into the top of a docstring, after line 1."""
    if docstring == '' or docstring is None:
        return text
    result = []
    splitted = textwrap.dedent(docstring).split('\n')
    first_line_done = False
    for line in splitted:
        if not first_line_done:
            if len(line) != 0:
                first_line_done = True
                result.append(line)
                for text_line in text.split('\n'):
                    result.append(text_line)
            else:
                result.append(line)
        else:
            result.append(line)
    return '\n'.join(result)