code: def p_case_block(self, p):
          
          statements = []
          for s in p[2:-1]:
              if isinstance(s, list):
                  for i in s:
                      statements.append(i)
              elif isinstance(s, self.asttypes.Default):
                  statements.append(s)
          p[0] = self.asttypes.CaseBlock(statements)
          p[0].setpos(p)
docs: case_block \
              : LBRACE case_clauses_opt RBRACE
              | LBRACE case_clauses_opt default_clause case_clauses_opt RBRACE