null==a&&(a=c||0);return Number(a)},getColor:function(a,b,c){a=null!=a?a[b]:null;null==a?a=c:a==mxConstants.NONE&&(a=null);return a},isEmptyObject:function(a){for(var b in a)return!1;return!0},clone:function(a,b,c){c=null!=c?c:!1;var d=null;if(null!=a&&"function"==typeof a.constructor)if(a.constructor===Element)d=a.cloneNode(null!=c?!c:!1);else{d=new a.constructor;for(var e in a)e!=mxObjectIdentity.FIELD_NAME&&(null==b||0>mxUtils.indexOf(b,e))&&(d[e]=c||"object"!=typeof a[e]?a[e]:mxUtils.clone(a[e]))}return d},