PDFBOX-5660: optimize, as suggested by Valery Bokov; closes #392

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1931167 13f79535-47bb-0310-9956-ffa450edef68

Author: THausherr

pdfbox/src/main/java/org/apache/pdfbox/text/PDFTextStripperByArea.java

@@ -117,7 +117,7 @@ public void extractRegions( PDPage page ) throws IOException
             setStartPage(getCurrentPageNo());
             setEndPage(getCurrentPageNo());
             // reset the stored text for the region so this class can be reused.
-            ArrayList<List<TextPosition>> regionCharactersByArticle = new ArrayList<>();
+            ArrayList<List<TextPosition>> regionCharactersByArticle = new ArrayList<>(1);
             regionCharactersByArticle.add(new ArrayList<>());
             regionCharacterList.put( regionName, regionCharactersByArticle );
             regionText.put( regionName, new StringWriter() );