/**
 * Returns the error message for the given error. When error is of type Error then the message property is read.
 * Otherwise the error is simply converted to a string.
 *
 * @param error - The error.
 * @returns The error message.
 */
export declare function getErrorMessage(error: unknown): string;
/**
 * Converts the given error object into an instance of the Error class. If it is already is an instance then it is returned unchanged. Otherwise it
 * is converted into a string and a new Error object is created using this string as error message.
 *
 * @param error - The error if unknown type.
 * @returns An Error instance.
 */
export declare function toError(error: unknown): Error;