diff --git a/contracts/interfaces/IOnchainIssuer.sol b/contracts/interfaces/IOnchainIssuer.sol
index b332cdb6..3ee60ee8 100644
--- a/contracts/interfaces/IOnchainIssuer.sol
+++ b/contracts/interfaces/IOnchainIssuer.sol
@@ -8,5 +8,6 @@ import {W3CLib} from "../lib/W3CLib.sol";
  */
 interface IOnchainIssuer {
     function getCredentials(uint256 _userId) external view returns (W3CLib.Credential[] memory);
+
     function issueCredential(uint256 _userId) external;
 }
diff --git a/contracts/lib/PrimitiveTypeUtils.sol b/contracts/lib/PrimitiveTypeUtils.sol
index 14de66eb..88fa856e 100644
--- a/contracts/lib/PrimitiveTypeUtils.sol
+++ b/contracts/lib/PrimitiveTypeUtils.sol
@@ -24,7 +24,6 @@ library PrimitiveTypeUtils {
             return swapped;
         }
      */
-    
     /**
      * @dev reverse uint256
      */
@@ -145,7 +144,7 @@ library PrimitiveTypeUtils {
      * @dev bytesToHex returns hex representation of bytes without '0x' prefix
      */
     function bytesToHex(bytes memory data) internal pure returns (string memory) {
-        bytes memory hexChars = '0123456789abcdef';
+        bytes memory hexChars = "0123456789abcdef";
         bytes memory hexString = new bytes(data.length * 2);
 
         for (uint i = 0; i < data.length; i++) {