removing toString from builder

Author: Otavio42

src/main/java/ru/lanwen/verbalregex/VerbalExpression.java

@@ -1,11 +1,10 @@
 package ru.lanwen.verbalregex;
 
+import static java.lang.String.valueOf;
+
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import static java.lang.String.valueOf;
-import static ru.lanwen.verbalregex.VerbalExpression.regex;
-
 public class VerbalExpression {
 
     private final Pattern pattern;
@@ -191,7 +190,7 @@ public Builder maybe(final String pValue) {
          * @return this builder
          */
         public Builder maybe(final Builder regex) {
-            return this.group().add(regex.build().toString()).endGr().add("?");
+            return this.group().add(regex).endGr().add("?");
         }
 
         /**