title: want to write header in csv from beanIO field name tag
body: <p>I want to write a header in csv file as my text file does not contain any header so i want to write it from beanIO field name tag</p>
  
  <p>I am having a beanIO with two stream one for reading and another for writing</p>
  
  <p>this is input file....
  textInput.txt-<br>
  1john dew  BA   xxx<br>
  1sam  hart MA   yyy  </p>
  
  <pre><code>public static void main(String[] args) throws Exception {
  
      StreamFactory factory = StreamFactory.newInstance();
  
      factory.load("C:\\Users\\PV5057094\\Demo_workspace\\XlsxMapper\\src\\main\\resources\\Employee.xml");
  
  
  BeanReader br = factory.createReader("EmployeeInfo",new File("C:\\Temp\\Soc\\textInput.txt"));
  
      BeanWriter out = factory.createWriter("EmployeeInfoCSV", new File("C:\\Temp\\Soc\\output.csv"));
  
  
  
      Object record;
  
      while ((record=br.read())!=null) {
  
  
          out.write(record);
  
          System.out.println("Record Written:" + record.toString());
  
      }
  
      // in.close();
      out.flush();
      out.close();
     }
  
  }
  
  
  BeanIO-
  
  &lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;beanio xmlns="http://www.beanio.org/2012/03"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://www.beanio.org/2012/03 http://www.beanio.org/2012/03/mapping.xsd"&gt;
  
      &lt;stream name="EmployeeInfo" format="fixedlength"&gt;
  
          &lt;record name="a" minOccurs="0" maxOccurs="unbounded"
              class="com.aexp.gmnt.imc.record.submission.Employee"&gt;
              &lt;field name="record" length="1" literal="1" rid="true"/&gt;
              &lt;field name="firstName" length="5"/&gt;
              &lt;field name="lastName" length="5"/&gt;
              &lt;field name="title" length="5"/&gt;
              &lt;field name="filler" length="5"/&gt;
          &lt;/record&gt;
  
      &lt;/stream&gt;
  
  
      &lt;stream name="EmployeeInfoCSV" format="csv"&gt;
          &lt;record name="a" minOccurs="0" maxOccurs="unbounded"
              class="com.aexp.gmnt.imc.record.submission.Employee"&gt;
              &lt;field name="record" length="1" literal="1" rid="true"/&gt;
              &lt;field name="firstName" length="5"/&gt;
              &lt;field name="lastName" length="5"/&gt;
              &lt;field name="title" length="5"/&gt;
              &lt;field name="filler" length="5"/&gt;
          &lt;/record&gt;
      &lt;/stream&gt;
  &lt;/beanio&gt;
  </code></pre>
  
  <p>Expected output-</p>
  
  <p>Record,FirstName,LastName,Title,Filler<br>
  1,john,dew,BA,xxx<br>
  1,sam,hart,MA,yyy</p>