code: def parse_pos_(self):
      # VOLT syntax doesn't seem to take device Y advance
      self.advance_lexer_()
      location = self.cur_token_location_
      assert self.is_cur_keyword_("POS"), location
      adv = None
      dx = None
      dy = None
      adv_adjust_by = {}
      dx_adjust_by = {}
      dy_adjust_by = {}
      if self.next_token_ == "ADV":
          self.advance_lexer_()
          adv = self.expect_number_()
          while self.next_token_ == "ADJUST_BY":
              adjustment, size = self.parse_adjust_by_()
              adv_adjust_by[size] = adjustment
      if self.next_token_ == "DX":
          self.advance_lexer_()
          dx = self.expect_number_()
          while self.next_token_ == "ADJUST_BY":
              adjustment, size = self.parse_adjust_by_()
              dx_adjust_by[size] = adjustment
      if self.next_token_ == "DY":
          self.advance_lexer_()
          dy = self.expect_number_()
          while self.next_token_ == "ADJUST_BY":
              adjustment, size = self.parse_adjust_by_()
              dy_adjust_by[size] = adjustment
      self.expect_keyword_("END_POS")
      return ast.Pos(
          adv, dx, dy, adv_adjust_by, dx_adjust_by, dy_adjust_by
      )
  
imports: import fontTools.voltLib.ast
  from fontTools.voltLib.lexer import Lexer
  from fontTools.voltLib.error import VoltLibError
  from io import open
label_desc: Use image node_id 19 for calling the Parser obj's underlying member method code with example usage: obj.parse_pos_() and returns: ast