code: function execCommand(command, ui, value, args) {
          var func, customCommand, state = 0;
  
          if (!/^(mceAddUndoLevel|mceEndUndoLevel|mceBeginUndoLevel|mceRepaint)$/.test(command) && (!args || !args.skip_focus)) {
            editor.focus();
          }
  
          args = editor.fire('BeforeExecCommand', { command: command, ui: ui, value: value });
          if (args.isDefaultPrevented()) {
            return false;
          }
  
          customCommand = command.toLowerCase();
          if ((func = commands.exec[customCommand])) {
            func(customCommand, ui, value);
            editor.fire('ExecCommand', { command: command, ui: ui, value: value });
            return true;
          }
  
          // Plugin commands
          each(editor.plugins, function (p) {
            if (p.execCommand && p.execCommand(command, ui, value)) {
              editor.fire('ExecCommand', { command: command, ui: ui, value: value });
              state = true;
              return false;
            }
          });
  
          if (state) {
            return state;
          }
  
          // Theme commands
          if (editor.theme && editor.theme.execCommand && editor.theme.execCommand(command, ui, value)) {
            editor.fire('ExecCommand', { command: command, ui: ui, value: value });
            return true;
          }
  
          // Browser commands
          try {
            state = editor.getDoc().execCommand(command, ui, value);
          } catch (ex) {
            // Ignore old IE errors
          }
  
          if (state) {
            editor.fire('ExecCommand', { command: command, ui: ui, value: value });
            return true;
          }
  
          return false;
        }
docs: Executes the specified command.
  
  @method execCommand
  @param {String} command Command to execute.
  @param {Boolean} ui Optional user interface state.
  @param {Object} value Optional value for command.
  @param {Object} args Optional extra arguments to the execCommand.
  @return {Boolean} true/false if the command was found or not.