[IMPROVEMENTS] Validation method Unit Test

[thiagonobrega]

Crate unit test for the validation implemented in the previous release:

• External URL Implement the Syncrnous set URL to a dARK pid  #13
• External PID Implement the Syncrnous set external pid to a dARK pid  #15
• Payload Implement the Syncrnous payload to a dARK pid  #14

THIS IS NOT A API TEST. IT IS A UNIT TEST ON THE VALIDATION METHOD

[thiagonobrega]

need discution