title: What parameters HasField function of protobuf expects?
body: <p>Consider following structure</p>
  
  <pre><code>message Fly {
    uint32 dtime = 1;
  }
  </code></pre>
  
  <p>But <code>HasField</code> function doesnt work:</p>
  
  <pre><code>&gt;&gt;&gt; d.ListFields()[0][0].name
  'dtime'
  &gt;&gt;&gt; d.ListFields()[0][0].full_name
  'Fly.dtime'
  &gt;&gt;&gt; 
  &gt;&gt;&gt; d.HasField('dtime')
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
    File "/.../lib/python2.7/site-packages/google/protobuf/internal/python_message.py", line 825, in HasField
      raise ValueError(error_msg % field_name)
  ValueError: Protocol message has no non-repeated submessage field "dtime"
  &gt;&gt;&gt; d.HasField('Fly.dtime')
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
    File "/.../lib/python2.7/site-packages/google/protobuf/internal/python_message.py", line 825, in HasField
      raise ValueError(error_msg % field_name)
  ValueError: Protocol message has no non-repeated submessage field "Fly.dtime"
  </code></pre>
  
  <p>What parameters does <code>HasField</code> expects?</p>