code: @Override
      public void writeStartTagStart(String localName)
          throws IOException, XMLStreamException
      {
          if (mCheckNames) {
              verifyNameValidity(localName, mNsAware);
          }
  
          int ptr = mOutputPtr;
          int extra = (mOutputBufLen - ptr) - (1 + localName.length());
          if (extra < 0) { // split on boundary, slower
              fastWriteRaw('<');
              fastWriteRaw(localName);
          } else {
              char[] buf = mOutputBuffer;
              buf[ptr++] = '<';
              int len = localName.length();
              localName.getChars(0, len, buf, ptr);
              mOutputPtr = ptr+len;
          }
      }
docs: /*
  //////////////////////////////////////////////////
  Write methods, elements
  //////////////////////////////////////////////////