code: public static void unescapeCsv(final Reader reader, final Writer writer)
              throws IOException {
  
          if (writer == null) {
              throw new IllegalArgumentException("Argument 'writer' cannot be null");
          }
  
          CsvEscapeUtil.unescape(reader, writer);
  
      }
docs: <p>
  Perform a CSV <strong>unescape</strong> operation on a <tt>Reader</tt> input, writing results
  to a <tt>Writer</tt>.
  </p>
  <p>
  This method is <strong>thread-safe</strong>.
  </p>
  
  @param reader the <tt>Reader</tt> reading the text to be unescaped.
  @param writer the <tt>java.io.Writer</tt> to which the unescaped result will be written. Nothing will
  be written at all to this writer if input is <tt>null</tt>.
  @throws IOException if an input/output exception occurs
  
  @since 1.1.2