code: function(column) {
          if(YAHOO.lang.isNumber(column) && this.keys[column]) {
              return this.keys[column];
          }
          else if(YAHOO.lang.isString(column)) {
              var allColumns = this.flat;
              var aColumns = [];
              for(var i=0; i<allColumns.length; i++) {
                  if(allColumns[i].key === column) {
                      aColumns.push(allColumns[i]);
                  }
              }
              if(aColumns.length === 1) {
                  return aColumns[0];
              }
              else if(aColumns.length > 1) {
                  return aColumns;
              }
          }
          return null;
      }
docs: Returns Column instance with given key or ColumnSet key index.
  
  @method getColumn
  @param column {String | Number} Column key or ColumnSet key index.
  @return {YAHOO.widget.Column} Column instance.