function addAnimation(oContainer, sSizeClass) {
		sSizeClass  = sSizeClass || "sapUiLocalBusyIndicatorAnimStandard";

		// determine automation size class
		var oAnimation = document.createElement("div");
		oAnimation.className = "sapUiLocalBusyIndicatorAnimation " + sSizeClass;
		oAnimation.appendChild(document.createElement("div"));
		oAnimation.appendChild(document.createElement("div"));
		oAnimation.appendChild(document.createElement("div"));


		oContainer.appendChild(oAnimation);
	}
Returns the HTML content for the busy indicator
styling + animation: LocalBusyIndicator.less

@param {string} sSize either "Large", "Medium" or "Section". Other sizes will be mapped to "Medium"
@returns {Element} the element for the busy indicator
@private
@ui5-restricted sap.ui.core, sap.chart