         
         for row in rowRange {
             
-            vectorElements.append(self.elements[row][column])
+            vectorElements.append(self.element(row, column))
         }
         
         return Vector(vectorElements)

        
        for column in columnRange {
            
            self.elements[row][column] = vector[column - columnRange.startIndex]
        }
    }
    

        
        for row in rowRange {
            
            self.setElement(atRow: row, atColumn: column, toElement: vector[row - rowRange.startIndex])
        }
    }
    
