code: def t_HEX_STRING(self, t):
          r'\'[0-9a-fA-F]*\'[hH]'
          value = t.value[1:-2]
          while value and value[0] == '0' and len(value) % 2:
              value = value[1:]
          # XXX raise in strict mode
          #    if len(value) % 2:
          #      raise error.PySmiLexerError("Number of symbols have to be even in hex string %s" % t.value, lineno=t.lineno)
          return f t_HEX_STRING(self, t):
          r'\'[0-9a-fA-F]*\'[hH]'
          value = t.value[1:-2]
          while value and value[0] == '0' and len(value) % 2:
              value = value[1:]
          # XXX raise in strict mode
          #    if len(value) % 2:
          #      raise error.PySmiLexerError("Number of symbols have to be even in hex string %s" % t.value, lineno=t.lineno)
          return t
docs: r'\'[0-9a-fA-F]*\'[hH]