Class Utils

Some utility functions which system provided:

• json: Convert to json format
• yaml: Convert to yaml format
• schema: Validate object schema
• base64: Convert to base64 string
• md5: Convert to md5 string
• sign: Format number (+1 or -1)
• random: Return random string
• lodash: Return lodash object. (https://lodash.com)

- Utils:
    toLower: txt => txt?.toLowerCase()
    toUpper: txt => txt?.toUpperCase()
###
- Echo: ${Utils.toLower('Hello world')}
- Echo: ${Utils.lodash.merge({a: 1}, {b: 2})}