MappingConfigurationDialog.show Method
        
 Tells the dialog to show itself. Those overriding can call this._super() to get a deferred object created for them.
 
         
        Parameters
        
            - mappings
            
 
            - 
                
Type: Array
ElementType: FlattenMappingsInfo
The mappings used to flatten the data. 
        
        Return Value
        
Type: jQuery.Promise
        
Value: Object
        
A promise object that is resolved when the dialog is complete,
 or rejected if it's cancelled. The dialog may return some specific information in the deferred.