Internal refactoring

Author: garydgregory

src/main/java/org/apache/commons/io/output/XmlStreamWriter.java

@@ -97,7 +97,7 @@ public Builder() {
          */
         @Override
         public XmlStreamWriter get() throws IOException {
-            return new XmlStreamWriter(getOutputStream(), getCharset());
+            return new XmlStreamWriter(this);
         }
 
     }
@@ -124,6 +124,11 @@ public static Builder builder() {
 
     private Charset charset;
 
+    @SuppressWarnings("resource") // caller closes.
+    private XmlStreamWriter(final Builder builder) throws IOException {
+        this(builder.getOutputStream(), builder.getCharset());
+    }
+
     /**
      * Constructs a new XML stream writer for the specified file
      * with a default encoding of UTF-8.