code: void validateIatAndExp(JwtClaims jwtClaims, long clockSkewInMilliseconds) throws InvalidClaimException {
  		if (jwtClaims == null) {
  			if (tc.isDebugEnabled()) {
  				Tr.debug(tc, "Missing JwtClaims object");
  			}
  			return;
  		}
  		NumericDate issueAtClaim = getIssuedAtClaim(jwtClaims);
  		NumericDate expirationClaim = getExpirationClaim(jwtClaims);
  
  		debugCurrentTimes(clockSkewInMilliseconds, issueAtClaim, expirationClaim);
  
  		validateIssuedAtClaim(issueAtClaim, expirationClaim, clockSkewInMilliseconds);
  		validateExpirationClaim(expirationClaim, clockSkewInMilliseconds);
  
  	}
docs: Validates the the {@value Claims#ISSUED_AT} and {@value Claims#EXPIRATION}
  claims are present and properly formed. Also verifies that the
  {@value Claims#ISSUED_AT} time is after the {@value Claims#EXPIRATION} time.