Tutorial "Exposing Several Services as a Single Service" payload incorrect

[lianescafarate]

Description:
When following the instructions of the tutorial Exposing Several Services as a Single Service, this payload doesn't work:

{"appointmentNumber":2,
"doctor":{
"name":"thomas collins",
"hospital":"grand oak community hospital",
"category":"surgery",
"availability":"9.00 a.m - 11.00 a.m",
"Fee":7000.0
},
"patient":{
"name":"John Doe",
"Dob":"1990-03-19",
"ssn":"234-23-525",
"address":"California",
"phone":"8770586755",
"email":"[email protected]"
},
"fee":7000.0,
"Confirmed":false,
"card_number":"1234567890"
}

Instead of 'Dob', it should be 'dob'.

Affected Product Version:
WSO2 Enterprise Integrator 6.6.0

OS, DB, other environment details and versions:
macOS Monterey Version 12.3.1
WSO2 Enterprise Integrator 6.6.0
Java 11.0.13
WSO Integrator Studio 8.0.1

Steps to reproduce:

1. Follow the tutorial.

2. Execute the command below on a terminal:
   curl --location --request POST 'http://localhost:9090/healthcare/payments'
   --header 'Content-Type: application/json'
   --data-raw '{"appointmentNumber":2,
   "doctor":{
   "name":"thomas collins",
   "hospital":"grand oak community hospital",
   "category":"surgery",
   "availability":"9.00 a.m - 11.00 a.m",
   "Fee":7000.0
   },
   "patient":{
   "name":"John Doe",
   "Dob":"1990-03-19",
   "ssn":"234-23-525",
   "address":"California",
   "phone":"8770586755",
   "email":"[email protected]"
   },
   "fee":7000.0,
   "Confirmed":false,
   "card_number":"1234567890"
   }'

3. Error presented: Exception occurred :null

• If you replace Dob with dob, it works fine, and the output is:
  {"patient":"John Doe","actualFee":7000.0,"discount":0,"discounted":7000.0,"paymentID":"7335bab0-cd2e-4eaa-94e2-4f0fc58e29c2","status":"Settled"}