Small bugfix

Author: shuklaalok7

client/src/main/java/in/clayfish/printful/models/Builder.java

@@ -1,17 +1,24 @@
 package in.clayfish.printful.models;
 
+import in.clayfish.printful.exceptions.ValidationFailedException;
+
 /**
  * @author shuklaalok7
  * @since 18/01/2017
  */
 public interface Builder<T> {
 
     /**
-     * @return
+     * @return Built object of type T
+     * @throws ValidationFailedException If {@link #check()} has been called and built object fails
+     *                                   basic validation constraints
      */
-    T build();
+    T build() throws ValidationFailedException;
 
     /**
+     * Once call to this method is chained, {@link #build()} can throw
+     * {@link ValidationFailedException} because it validates the objects after building it.
+     *
      * @return Builder object
      */
     Builder<T> check();

client/src/main/java/in/clayfish/printful/models/includable/Address.java

@@ -126,6 +126,7 @@ public Builder() {
             this.address = new Address();
         }
 
+        @Override
         public Builder check() {
             this.checkValidity = true;
             return this;
@@ -185,10 +186,7 @@ public Builder company(String company) {
             return this;
         }
 
-        /**
-         *
-         * @return
-         */
+        @Override
         public Address build() {
             if (checkValidity) {
                 checkValidity();
@@ -202,10 +200,10 @@ public Address build() {
         private void checkValidity() {
             if (this.address.country == null || this.address.country.getCode() == null || this.address.country.getCode().isEmpty()
                     || this.address.state == null || this.address.state.getCode() == null || this.address.state.getCode().isEmpty()
-                    || this.address.name == null || !this.address.name.isEmpty()
-                    || this.address.city == null || !this.address.city.isEmpty()
-                    || this.address.address1 == null || !this.address.address1.isEmpty()
-                    || this.address.zip == null || !this.address.zip.isEmpty()) {
+                    || this.address.name == null || this.address.name.isEmpty()
+                    || this.address.city == null || this.address.city.isEmpty()
+                    || this.address.address1 == null || this.address.address1.isEmpty()
+                    || this.address.zip == null || this.address.zip.isEmpty()) {
                 throw new ValidationFailedException();
             }
         }