fix: get empty field

Author: cedriking

src/lib/transaction.ts

@@ -45,6 +45,7 @@ export default class Transaction extends BaseObject implements TransactionInterf
     jwk: JWKInterface | 'use_wallet' = 'use_wallet',
   ) {
     super();
+
     Object.assign(this, attributes);
 
     // If something passes in a Tx that has been toJSON'ed and back,

src/utils/baseObject.ts

@@ -12,11 +12,7 @@ export class BaseObject implements BaseObjectInterface {
 
     // Handle fields that are Uint8Array.
     // To maintain compatibility, we encode them to b64url, only if the decode option is not specified.
-    if (typeof this[field] === null) {
-      throw new Error(`Field "${field}" not set.`);
-    }
-
-    if (this[field].constructor.name === 'Uint8Array') {
+    if (this[field] && this[field].constructor.name === 'Uint8Array') {
       if (options && options.decode && options.string) {
         return bufferToString(this[field]);
       }