/**
 * Error thrown when a feature is not yet implemented.
 */ export class UnimplementedError extends Error { param message returns public constructor ( message ? ) { super ( message ) ; Object . setPrototypeOf ( this , new . target . prototype ) ; } } /**
 * Error thrown when a string fails to parse.
 */ export class ParseError extends Error { param message returns public constructor ( message ? ) { super ( message ) ; Object . setPrototypeOf ( this , new . target . prototype ) ; } }