Function trim

libs/echarts/echarts.simple.js:819–829

* @memberOf module:zrender/core/util * @param {string} str string to be trimed * @return {string} trimed string

(str)

 * @return {string} trimed string
 */
function trim(str) {
    if (str == null) {
        return null;
    }
    else if (typeof str.trim === 'function') {
        return str.trim();
    }
    else {
        return str.replace(/^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g, '');
    }
}

var primitiveKey = '__ec_primitive__';
/**