title: NULL value in U-SQL replaces zero-length string when giving nullEscape Parameter
body: <p>I had used nullEscape parameter in the U-SQL query. It replaced the \N to zero-length string. Is there any way to transform \N to "\N" using U-SQL query.</p>
  
  <blockquote>
    <p>Value1,(zero-length string),value2,value3,(zero-length string),(zero-length string)</p>
  </blockquote>
  
  <p>I'm also having a doubt of <strong>I want to \N as well as don't need to change \N to Zero-length string in the Extractor while skiping the null values like \N?</strong></p>
  
  <pre><code>I have tried the following but it didn't worked,
  USING Extractors.Csv(nullEscape:"\N");
  </code></pre>
  
  <p>Sample CSV Data:</p>
  
  <blockquote>
    <p>Name,,,"",Address,Pin</p>
  </blockquote>
  
  <p>\N has already been replaced with Zero-length String.</p>