code: public void setRequestHeader(String header, String value) {
          LOG.entering(CLASS_NAME, "setRequestHeader", new Object[] {header, value});
          HttpRequestUtil.validateHeader(header);
          connection.addRequestProperty(header, value);
      }
docs: /* (non-Javadoc)
  @see org.kaazing.gateway.bridge.HttpRequestDelegate#setRequestHeader(java.lang.String, java.lang.String)