human
I wrote the below code

    def find_last_line_numbers(lines):
        u'Return    a    tuple    of    the    last    line    numbers    in    the    given    list    of    lines.\n\n                                The    last    line    numbers    are    not    always    contained    in    the    last    element    of\n                                the    ``lines``    list.    This    is    the    case    when    dealing    with    interdiffs    that\n                                have    filtered    out    opcodes.\n\n                                See    :py:func:`get_chunks_in_range`    for    a    description    of    what    is\n                                contained    in    each    element    of    ``lines``.\n                                '
        last_left = None
        last_right = None
        for line in reversed(lines):
            if ((not last_right) and line[4]):
                last_right = line[4]
            if ((not last_left) and line[1]):
                last_left = line[1]
            if (last_left and last_right):
                break
        return (last_left, last_right)
    def find_header(headers, offset, last_line):
        u'Return    the    last    header    that    occurs    before    a    line.\n\n                                The    offset    parameter    is    the    difference    between    the    virtual    number    and\n                                and    actual    line    number    in    the    chunk.    This    is    required    because    the\n                                header    line    numbers    are    original    or    patched    line    numbers,    not    virtual\n                                line    numbers.\n                                '
        end_line = min(last_line, target_line)
        for header in reversed(headers):
            virtual_line = (header[0] + offset)
            if (virtual_line < end_line):
                return {u'line': virtual_line, u'text': header[1]}
    header = {u'left': None, u'right': None}
    for chunk in chunks:
       ...

What's a good function header?
 ... Here's a good function header?
assistant
#Here's a good function header.

def _get_last_header_in_chunks_before_line(chunks, target_line):