code: def query_band(self, value):
          
  
          self._query_band = value
          # If query band is None we remove the element and don't write it to XML
          if value is None:
              try:
                  del self._connectionXML.attrib['query-band-spec']
              except KeyError:
                  pass
          else:
              self._connectionXML.set('query-band-spec', value)
docs: Set the connection's query_band property.
  
          Args:
              value:  New query_band value. String.
  
          Returns:
              Nothing.