/**
 * Formats an array of strings to a comma-separated string in uppercase
 * @param extensions Array of allowed file extensions
 * @param collapseExtensionsAfter Maximum number of extensions to display
 * @returns Formatted string, e.g.: "JPG, JPEG, JP2, PNG"
 */
export declare const formatExtensions: (extensions: Array<string>, collapseExtensionsAfter: number) => string;
/**
 * Formats file size to a human readable file size string from a number
 * @param fileSize File size in bytes
 * @param round Decimal place, default is 1
 * @returns Formatted file size string
 */
export declare const formatFileSize: (fileSize: number, round?: number) => string;