code: def set_setting(key, value, qsettings=None):
      
      full_key = '%s/%s' % (APPLICATION_NAME, key)
      set_general_setting(full_key, value, qsettings)
docs: Set value to QSettings based on key in InaSAFE scope.
  
      :param key: Unique key for setting.
      :type key: basestring
  
      :param value: Value to be saved.
      :type value: QVariant
  
      :param qsettings: A custom QSettings to use. If it's not defined, it will
          use the default one.
      :type qsettings: qgis.PyQt.QtCore.QSettings