image_size_input_fields

 * @return string|null
 */
function media_upload_library() {
	$errors = array();

	if ( ! empty( $_POST ) ) {
		$return = media_upload_form_handler();

		if ( is_string( $return ) ) {
			return $return;
		}
		if ( is_array( $return ) ) {
			$errors = $return;
		}
	}

	return wp_iframe( 'media_upload_library_form', $errors );
}

/**
 * Retrieve HTML for the image alignment radio buttons with the specified one checked.
 *
 * @since 2.7.0
 *
 * @param WP_Post $post
 * @param string  $checked
 * @return string
 */
function image_align_input_fields( $post, $checked = '' ) {

	if ( empty( $checked ) ) {
		$checked = get_user_setting( 'align', 'none' );
	}

	$alignments = array(
		'none'   => __( 'None' ),
		'left'   => __( 'Left' ),
		'center' => __( 'Center' ),
		'right'  => __( 'Right' ),
	);

	if ( ! array_key_exists( (string) $checked, $alignments ) ) {
		$checked = 'none';
	}

	$out = array();

	foreach ( $alignments as $name => $label ) {
		$name  = esc_attr( $name );
		$out[] = "<input type='radio' name='attachments[{$post->ID}][align]' id='image-align-{$name}-{$post->ID}' value='$name'" .
			( $checked == $name ? " checked='checked'" : '' ) .
			" /><label for='image-align-{$name}-{$post->ID}' class='align image-align-{$name}-label'>$label</label>";
	}

	return join( "\n", $out );
}

/**
 * Retrieve HTML for the size radio buttons with the specified one checked.
 *
 * @since 2.7.0
 *
 * @param WP_Post     $post
 * @param bool|string $check
 * @return array
 */
function image_size_input_fields( $post, $check = '' ) {