Parse a docstring into title and description.

    Args
    ----
    doc : str
        A docstring, optionally with a title line, separated from a description
        line by at least one blank line.

    Returns
    -------
    title : str
        The first line of the docstring.
    description : str
        The rest of a docstring.

def _parse_doc(doc=''):
    """Parse a docstring into title and description.

    Args
    ----
    doc : str
        A docstring, optionally with a title line, separated from a description
        line by at least one blank line.

    Returns
    -------
    title : str
        The first line of the docstring.
    description : str
        The rest of a docstring.

    """
    title, description = '', ''
    if doc:
        sp = doc.split('\n', 1)
        title = sp[0].strip()
        if len(sp) > 1:
            description = textwrap.dedent(sp[1]).strip()
    return (title, description)