human
Complete the below
@util.positional(1)
def encode_message(message, prefix=''):

    ''''Encode Message instance to url-encoded string.
    Args:
    message: Message instance to encode in to url-encoded string.
    prefix: Prefix to append to field names of contained values.
    Returns:
    String encoding of Message in URL encoded format.
    Raises:
    messages.ValidationError if message is not initialized.'
    '''
 ... What is a Python program to fix to append to field names of contained values?
assistant
#Here is Python program to fix to append to field names of contained values.
    message.check_initialized()
    parameters = []
    def build_message(parent, prefix):
        'Recursively    build    parameter    list    for    URL    response.\n\n                Args:\n                        parent:    Message    to    build    parameters    for.\n                        prefix:    Prefix    to    append    to    field    names    of    contained    values.\n\n                Returns:\n                        True    if    some    value    of    parent    was    added    to    the    parameters    list,\n                        else    False,    meaning    the    object    contained    no    values.\n                '
        has_any_values = False
        for field in sorted(parent.all_fields(), key=(lambda f: f.number)):
            next_value = parent.get_assigned_value(field.name)
            if (next_value is None):
                continue
            has_any_values = True
            if (not field.repeated):
                next_value = [next_value]
            for (index, item) in enumerate(next_value):
                if field.repeated:
                    field_name = ('%s%s-%s' % (prefix, field.name, index))
                else:
                    field_name = (prefix + field.name)
                if isinstance(field, message_types.DateTimeField):
                    parameters.append((field_name, item.isoformat()))
                elif isinstance(field, messages.MessageField):
                    if (not build_message(item, (field_name + '.'))):
                        parameters.append((field_name, ''))
                elif isinstance(field, messages.BooleanField):
                    parameters.append((field_name, ((item and 'true') or 'false')))
                else:
                    if isinstance(item, unicode):
                        item = item.encode('utf-8')
                    parameters.append((field_name, str(item)))
        return has_any_values
    build_message(message, prefix)
    for key in message.all_unrecognized_fields():
        (values, _) =...