code: function(character) {
          var f = utilDate.formatCodes[character];
  
          if (f) {
            f = typeof f == 'function'? f() : f;
            utilDate.formatCodes[character] = f; // reassign function result to prevent repeated execution
          }
  
          // note: unknown characters are treated as literals
          return f || ("'" + Ext.String.escape(character) + "'");
      }
docs: private