TableRow.get("field_name") can only be cast to String in Dataflow ParDo
<p>I am exporting a table from BQ by dataflow and it seems when processed by ParDo, I could only get the "string" value of data of each field in <code>TableRow</code> regardless of what originally the data type is in BQ schema. </p>

<p>For example, say my table has a <code>INTEGER</code> typed column "fieldA":</p>

<pre><code>     public void processElement(ProcessContext c) throws Exception {
         TableRow row = c.element();
         String str = (String) c.get("fieldA"); // OK
         Integer i = (Integer) c.get("fieldA"); // Throw "String cannot be cast to Integer" exception
     }
</code></pre>

<p>Is it a bug or it is only me? If not only me, is there anyway to get around it? For integer type I could still do <code>Integer.valueOf(String)</code> but it will have to be a little bit hacky and err-prone when parsing <code>Timestamp</code> field.</p>

<p>FYI, I am using BlockDataflowPipelineRunner</p>