old_contents: /**
   * Validation utilities.
   *
   * Site Kit by Google, Copyright 2021 Google LLC
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /**
   * Checks if the given publication ID appears to be a valid.
   *
   * @since n.e.x.t
   *
   * @param {string} publicationID Publication ID to test.
   * @return {boolean} `true` if the given publication ID is valid, `false` otherwise.
   */
  export function isValidPublicationID( publicationID ) {
  	return (
  		typeof publicationID === 'string' &&
  		/^[A-Za-z0-9_.-]+$/.test( publicationID )
  	);
  }
  
  /**
   * Checks if the given color theme is valid.
   *
   * @since n.e.x.t
   *
   * @param {string} colorTheme Color theme to test.
   * @return {boolean} `true` if the given color theme is valid, `false` otherwise.
   */
  export function isValidColorTheme( colorTheme ) {
  	return typeof colorTheme === 'string' && colorTheme !== '';
  }
  
  /**
   * Checks if the given button placement is valid.
   *
   * @since n.e.x.t
   *
   * @param {string} buttonPlacement Button placement to test.
   * @return {boolean} `true` if the given button placement is valid, `false` otherwise.
   */
  export function isValidButtonPlacement( buttonPlacement ) {
  	return typeof buttonPlacement === 'string' && buttonPlacement !== '';
  }
  
  /**
   * Checks if the given buttonPostTypes array is valid.
   *
   * @since n.e.x.t
   *
   * @param {string[]} buttonPostTypes Button post types to test.
   * @return {boolean} `true` if the given products list is valid, `false` otherwise.
   */
  export function isValidButtonPostTypes( buttonPostTypes ) {
  	return (
  		Array.isArray( buttonPostTypes ) &&
  		buttonPostTypes.length >= 1 &&
  		buttonPostTypes.every( ( buttonPostType ) => buttonPostType.length > 0 )
  	);
  }
  
new_contents: /**
   * Validation utilities.
   *
   * Site Kit by Google, Copyright 2021 Google LLC
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /**
   * Checks if the given publication ID appears to be a valid.
   *
   * @since n.e.x.t
   *
   * @param {string} publicationID Publication ID to test.
   * @return {boolean} `true` if the given publication ID is valid, `false` otherwise.
   */
  export function isValidPublicationID( publicationID ) {
  	return (
  		typeof publicationID === 'string' &&
  		/^[A-Za-z0-9_.-]+$/.test( publicationID )
  	);
  }
  
  /**
   * Checks if the given color theme is valid.
   *
   * @since n.e.x.t
   *
   * @param {string} colorTheme Color theme to test.
   * @return {boolean} `true` if the given color theme is valid, `false` otherwise.
   */
  export function isValidColorTheme( colorTheme ) {
  	return typeof colorTheme === 'string' && colorTheme !== '';
  }
  
  /**
   * Checks if the given button placement is valid.
   *
   * @since n.e.x.t
   *
   * @param {string} buttonPlacement Button placement to test.
   * @return {boolean} `true` if the given button placement is valid, `false` otherwise.
   */
  export function isValidButtonPlacement( buttonPlacement ) {
  	return typeof buttonPlacement === 'string' && buttonPlacement !== '';
  }
  
  /**
   * Checks if the given buttonPostTypes array is valid.
   *
   * @since n.e.x.t
   *
   * @param {string[]} buttonPostTypes Button post types to test.
   * @return {boolean} `true` if the given button post types list is valid, `false` otherwise.
   */
  export function isValidButtonPostTypes( buttonPostTypes ) {
  	return (
  		Array.isArray( buttonPostTypes ) &&
  		buttonPostTypes.length >= 1 &&
  		buttonPostTypes.every( ( buttonPostType ) => buttonPostType.length > 0 )
  	);
  }
  
subject: Update JSDoc.