code: @Override
      public StringWriter append(CharSequence csq) {
          if (csq == null)
              append("null"); //$NON-NLS-1$
          else {
      		int len = csq.length();
      		for (int i = 0; i < len; i++) {
      			append(csq.charAt(i));
      		}
          }
          return this;
      }
docs: /* (non-Javadoc)
  @see java.io.StringWriter#append(java.lang.CharSequence)