}

sub headers_as_string {
    shift->{'_headers'}->as_string(@_);
}


sub content  {

    my $self = $_[0];
    if (defined(wantarray)) {
	$self->_content unless exists $self->{_content};
	my $old = $self->{_content};
	$old = $$old if ref($old) eq "SCALAR";
	&_set_content if @_ > 1;
	return $old;
    }

    if (@_ > 1) {
	&_set_content;
    }
    else {
	Carp::carp("Useless content call in void context") if $^W;
    }
}


sub _set_content {
    my $self = $_[0];
    _utf8_downgrade($_[1]);
    if (!ref($_[1]) && ref($self->{_content}) eq "SCALAR") {
	${$self->{_content}} = $_[1];
    }
    else {
	die "Can't set content to be a scalar reference" if ref($_[1]) eq "SCALAR";
	$self->{_content} = $_[1];
	delete $self->{_content_ref};
    }
    delete $self->{_parts} unless $_[2];
}


sub add_content
{
    my $self = shift;
    $self->_content unless exists $self->{_content};
    my $chunkref = \$_[0];
    $chunkref = $$chunkref if ref($$chunkref);  # legacy

    _utf8_downgrade($$chunkref);

    my $ref = ref($self->{_content});
    if (!$ref) {
	$self->{_content} .= $$chunkref;
    }
    elsif ($ref eq "SCALAR") {
	${$self->{_content}} .= $$chunkref;
    }
    else {
	Carp::croak("Can't append to $ref content");
    }
    delete $self->{_parts};
}

sub add_content_utf8 {
    my($self, $buf)  = @_;
    utf8::upgrade($buf);
    utf8::encode($buf);
    $self->add_content($buf);
}

sub content_ref
{
    my $self = shift;
    $self->_content unless exists $self->{_content};
    delete $self->{_parts};
    my $old = \$self->{_content};
    my $old_cref = $self->{_content_ref};
    if (@_) {
	my $new = shift;
	Carp::croak("Setting content_ref to a non-ref") unless ref($new);
	delete $self->{_content};  # avoid modifying $$old
	$self->{_content} = $new;
	$self->{_content_ref}++;
    }
    $old = $$old if $old_cref;
    return $old;
}


sub decoded_content
{
    my($self, %opt) = @_;
    my $content_ref;
    my $content_ref_iscopy;

    eval {

	require HTTP::Headers::Util;
	my($ct, %ct_param);