HeaderField getHeaderField(int index) {
    HeaderEntry entry = head;
    while(index-- >= 0) {
      entry = entry.before;
    }
    return entry;
  }
HeaderField getHeaderField(int index) {
    HeaderEntry entry = head;
    while(index-- >= 0) {
      entry = entry.before;
    }
    return entry;
  }
HeaderField getHeaderField ( int index ) { HeaderEntry entry = head ; while ( index -- >= 0 ) { entry = entry . before ; } return entry ; }
Return the header field at the given index.
Exposed for testing.
Return the header field at the given index . Exposed for testing .