code: def has_header(self, hdrclass):
          '''
          Return True if the packet has a header of the given hdrclass, 
          False otherwise.
          '''
          if isinstance(hdrclass, str):
              return self.get_header_by_name(hdrclass) is not None
          return self.get_header(hdrclass) is not Nonf has_header(self, hdrclass):
          '''
          Return True if the packet has a header of the given hdrclass, 
          False otherwise.
          '''
          if isinstance(hdrclass, str):
              return self.get_header_by_name(hdrclass) is not None
          return self.get_header(hdrclass) is not None
docs: Return True if the packet has a header of the given hdrclass, 
          False otherwise.