Visibility hidden
    Spec
    
    Setting a table to visibility:hidden, but rows and cells to different nested visibility values.
    Height and width of table should not change.
    
    
      
        
            
                row 1
            
            
                
            
        
        
            
                row 1
            
            
                
            
        
      
    
    Bottom table is identical to top except entire row group of two rows is hidden, and
    first row is visible with two hidden cells and a visible span in the left cell.
    
      
        
            
                row 1
            
            
                
            
        
        
            
                row 1