text: const joi = require('@hapi/joi');
  
  const centerIdSchema = joi.string().regex(/^[0-9a-fA-F]{24}$/);
  const centerNameSchema = joi.string().max(140);
  const centerDescriptionSchema = joi.string();
  
  const createCenterSchema = {
    name: centerNameSchema.required(),
    description: centerDescriptionSchema.required()
  };
  
  const updateCenterSchema = {
    name: centerNameSchema,
    description: centerDescriptionSchema
  };
  
  module.exports = {
    centerIdSchema,
    createCenterSchema,
    updateCenterSchema
  };
  