message: add back return types
diff: @@ -39,7 +39,7 @@ export const color = new Proxy(chalk, {
  export class UX {
  // Collection of warnings that can be accessed and manipulated later.
  - public static warnings = new Set<string>();
  + public static warnings: Set<string> = new Set<string>();
  /**
  * Formats a deprecation warning for display to `stderr`, `stdout`, and/or logs.
  @@ -47,7 +47,7 @@ export class UX {
  * @param def The definition for the deprecated object.
  * @returns {string} The formatted deprecation message.
  */
  - public static formatDeprecationWarning(def: DeprecationDefinition) {
  + public static formatDeprecationWarning(def: DeprecationDefinition): string {
  let msg = def.messageOverride || `The ${def.type} "${def.name}" has been deprecated and will be removed in v${(def.version + 1)}.0 or later.`;
  if (def.to) {
  msg += ` Use "${def.to}" instead.`;
  @@ -63,7 +63,7 @@ export class UX {
  *
  * @returns {Promise<UX>} A `Promise` of the created `UX` instance.
  */
  - public static async create() {
  + public static async create(): Promise<UX> {
  return new UX(await Logger.child('UX'));
  }
  @@ -82,7 +82,7 @@ export class UX {
  *
  * @returns {UX}
  */
  - public log(...args: any[]) {
  + public log(...args: any[]): UX {
  if (this.isOutputEnabled) {
  this.cli.log(...args);
  }
  @@ -119,7 +119,7 @@ export class UX {
  * @returns {UX}
  * @see UX.warnings
  */
  - public warn(message: string) {
  + public warn(message: string): UX {
  const warning: string = color.yellow('WARNING:');
  // Necessarily log to sfdx.log.
  @@ -142,7 +142,7 @@ export class UX {
  *
  * @returns {UX}
  */
  - public error(...args: any[]) {
  + public error(...args: any[]): UX {
  if (this.isOutputEnabled) {
  console.error(...args);
  }
  @@ -159,7 +159,7 @@ export class UX {
  * @returns {UX}
  * @throws {TypeError} If the object is not JSON-serializable.
  */
  - public errorJson(obj: object) {
  + public errorJson(obj: object): UX {
  const err = JSON.stringify(obj, null, 4);
  console.error(err);
  this.logger.error(err);
  @@ -174,7 +174,7 @@ export class UX {
  * @param options The table options to use for formatting.
  * @returns {UX}
  */
  - public table(rows: any[], options: Partial<SfdxTableOptions> = {}) {
  + public table(rows: any[], options: Partial<SfdxTableOptions> = {}): UX {
  if (this.isOutputEnabled) {
  const columns = _.get(options, 'columns');
  if (columns) {
  @@ -209,7 +209,7 @@ export class UX {
  * @param keys The object keys to be written to stdout.
  * @returns {UX}
  */
  - public styledObject(obj: any, keys?: string[]) {
  + public styledObject(obj: any, keys?: string[]): UX {
  this.logger.info(obj);
  if (this.isOutputEnabled) {
  this.cli.styledObject(obj, keys);
  @@ -238,7 +238,7 @@ export class UX {
  * @param header The header to be styled.
  * @returns {UX}
  */
  - public styledHeader(header: string) {
  + public styledHeader(header: string): UX {
  this.logger.info(header);
  if (this.isOutputEnabled) {
  this.cli.styledHeader(header);
  