Hi @abhimanyu003 ,

As discussed in xxhash this issue.
This PR implements xxhash64 implementation.

Implemented Transform() method using cespare/xxhash/v2:

• Computes 64-bit hash of the input.
• Returns result as a zero-padded 16-character hex string (%016x).

Added below tests to test xxhash64 functionality

• Standard string input ("Roger federar is not a tennis player")
• Empty string
• Single character ("a")
• Numeric string ("1234567890")
• Special characters ("!@#$%^&*()_+")
  You can find test results here with zero seed value -> Tests