Class constructor Ajv cannot be invoked without 'new' code example

Example 1: TypeError: Class constructor Model cannot be invoked without

// tsconfig.json
{
    "compilerOptions": {
        "target": "es6"
    }
}

Example 2: Class constructor cannot be invoked without new

{
        "compilerOptions": {
            "target": "ES6",
            ...
        }
    }