code: def parse_adjust_single_(self):
      assert self.is_cur_keyword_("ADJUST_SINGLE")
      location = self.cur_token_location_
      adjust_single = []
      while self.next_token_ != "END_ADJUST":
          coverages = self.parse_coverage_()
          self.expect_keyword_("BY")
          pos = self.parse_pos_()
          adjust_single.append((coverages, pos))
      self.expect_keyword_("END_ADJUST")
      position = ast.PositionAdjustSingleDefinition(
          adjust_single, location=location
      )
      return position
  
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 16 for calling the Parser obj's underlying member method code with example usage: obj.parse_adjust_single_() and returns: position