code: function(selector, all) {
  		if (!this.querySelector) {bb.warn('Find should be used with DOM elements'); return;}
  		return all && this.querySelectorAll(selector) || this.querySelector(selector);
  	}
docs: Finds child element matching provided selector
  @param {string} selector - Selector has limitations based on the browser support.
  @param {boolean} all - Flag to find all matching elements. Otherwise fist found element is returned.
  @return {element|array|undefined} - Found element or array of elements