question: public void insertColumn ( int columnIndex , ColumnSpec columnSpec ) { if ( columnIndex < 1 || columnIndex > getColumnCount ( ) ) { throw new IndexOutOfBoundsException ( "The column index " + columnIndex + "must be in the range [1, " + getColumnCount ( ) + "]." ) ; } colSpecs . add ( columnIndex - 1 , columnSpec ) ; shiftComponentsHorizontally ( columnIndex , false ) ; adjustGroupIndices ( colGroupIndices , columnIndex , false ) ; }
target:  Inserts the specified column at the specified position. Shifts components that intersect the new column to the right hand side and readjusts column groups.<p> The component shift works as follows: components that were located on the right hand side of the inserted column are shifted one column to the right; component column span is increased by one if it intersects the new column.<p> Column group indices that are greater or equal than the given column index will be increased by one.