header property
      
      set
      header
      (String? value) 
      
    
    
Setter for tooltip header text
Implementation
set header(String? value) {
  if (_header == value) {
    return;
  }
  _header = value;
}Setter for tooltip header text
set header(String? value) {
  if (_header == value) {
    return;
  }
  _header = value;
}