code: def stack_effect(self) -> StackEffect | None:
      #   IDENTIFIER [':' [IDENTIFIER [TIMES]] ['&' '(' IDENTIFIER ['+' IDENTIFIER] ')']] ['if' '(' expression ')']
      # | IDENTIFIER '[' expression ']'
      if tkn := self.expect(lx.IDENTIFIER):
          type_text = ""
          type_prop = None
          if self.expect(lx.COLON):
              if i := self.expect(lx.IDENTIFIER):
                  type_text = i.text.strip()
                  if self.expect(lx.TIMES):
                      type_text += " *"
              if self.expect(lx.AND):
                  consumed_bracket = self.expect(lx.LPAREN) is not None
                  type_prop_text = self.require(
                      lx.IDENTIFIER
                  ).text.strip()
                  refinement = None
                  if self.expect(lx.PLUS):
                      refinement = self.require(
                          lx.IDENTIFIER
                      ).text.strip()
                  type_prop = (type_prop_text, refinement)
                  if consumed_bracket:
                      self.require(lx.RPAREN)
          cond_text = ""
          if self.expect(lx.IF):
              self.require(lx.LPAREN)
              if not (cond := self.expression()):
                  raise self.make_syntax_error("Expected condition")
              self.require(lx.RPAREN)
              cond_text = cond.text.strip()
          size_text = ""
          if self.expect(lx.LBRACKET):
              if type_text or cond_text:
                  raise self.make_syntax_error("Unexpected [")
              if not (size := self.expression()):
                  raise self.make_syntax_error("Expected expression")
              self.require(lx.RBRACKET)
              type_text = "PyObject **"
              size_text = size.text.strip()
          return StackEffect(
              tkn.text, type_text, cond_text, size_text, type_prop
          )
      return None
  
imports: from dataclasses import dataclass, field
  from typing import NamedTuple, Callable, TypeVar, Literal, cast
  import lexer
  from plexer import PLexer
label_desc: Use image node_id 10 for calling the Parser obj's underlying member method code with example usage: obj.stack_effect() and returns: None, StackEffect