docs: function(a){
              if(!a || !this.isArray(a)) return; 
  
              var i = 0,start = 0,len = a.length;
  
              for(;i < len; i++){
               if(!this.isUndefined(a[i]) && !this.isNull(a[i]) && !(this.isEmpty(a[i]))){
                a[start]=a[i];
                start += 1;
              }
            }
  
            a.length = start;
            return a;
      }