public JTableHeader(TableColumnModel cm)
public JTableHeader()
  public JTableHeader(TableColumnModel cm)  {    accessibleContext = new AccessibleJTableHeader();    columnModel = cm == null ? createDefaultColumnModel() : cm;     draggedColumn = null;    draggedDistance = 0;    opaque = true;    reorderingAllowed = true;    resizingAllowed = true;    resizingColumn = null;    table = null;    updateTableInRealTime = true;    cellRenderer = createDefaultRenderer();    updateUI();  }