code: function HttpHandler(url, method, headers) {
  	method = typeof method !== 'undefined' ? method : 'GET';
  	headers = headers || {};
  
  	Handler.call(this);
  
  	if (method !== 'GET' && method !== 'POST') {
  		throw new Error('Argument 4 of HttpHandler.constructor has unsupported'
  			+ ' value \'' + method + '\'');
  	}
  
  	if (method === 'GET') {
  		this._strategy = new HttpGetStrategy(url, headers);
  
  	} else {
  		this._strategy = new HttpPostStrategy(url, headers);
  	}
  }
docs: ------------------------------------------------------------------------------ HTTP handlers ------------------------------------------------------------------------------ 
  A class which sends records to a Web server, using either GET or
  POST semantics.
  
  @constructor HttpHandler
  @extends Handler
  @param {string} url
  @param {string} [method=GET]
  @param {Object} [headers]