/**
 * Returns the full name of an Error instance or constructor.
 *
 * @remarks
 * If no fullName property is found, this function attempts to determine one
 * based on the name property. If the name is simply 'Error', then so too is the
 * fullName. If the name ends with 'Error', then the fullName will be the name
 * appended to 'Error', separated by a dot. This enables some support for error
 * classes that are not subclasses of NaniError, by assuming they're at least
 * instances of Error.
 *
 * @param err - An Error instance or constructor. If omitted or falsy, this
 *   function will return null.
 * @returns Full name if it can be determined, null otherwise.
 */
export declare function getFullName(err?: Error | Function | null): string | null;