Get the two arguments of the current AST node

@param {Array} astList
@param {Object} context
@param {Function} callback
function (astList, context, callback) {
	var retval = new Array(2);
	var i = 0;
	var getOpArgs2_callback = function (err, val) {
		if (err) {
			callback(err);
		} else {
			retval[i] = val;
			i++;
			if (i >= 2) callback(null, retval);
		}
	};
	run(astList[1], context, getOpArgs2_callback);
	run(astList[2], context, getOpArgs2_callback);
}