code: function ( target, callback ) {
              if ( typeof Array.prototype.filter === 'function' ) {
                  this.filter = function ( target, callback ) {
                      if ( this.is(target) ) {
                          return target.filter( callback );
                      } else {
                          throw new Error('[ixBand] "filter()" ' + MSG_NOT_ARRAY);
                      }
                  };
              } else {
                  this.filter = function ( target, callback ) {
                      if ( this.is(target) ) {
                          var tArray = target,
                              aryNum = tArray.length,
                              result = [], i;
      
                          for ( i = 0; i < aryNum; ++i ) {
                              var ary = tArray[i],
                                  state = callback.call( this , ary, i, tArray );
                              if ( state == true ) result.push( ary );
                          }
                          return result;
                      } else {
                          throw new Error('[ixBand] "filter()" ' + MSG_NOT_ARRAY);
                      }
                  };
              }
      
              return this.filter( target, callback );
          }
docs: 지정된 함수에 대해 true를 반환하는 모든 항목이 포함된 새 배열을 반환.
  @param	{Array}			target		대상 배열
  @param	{Function}		callback	function callback(item:*, index:int, array:Array):Boolean;
  @return	{Array}