code: def scan_until_(self, stop_at):
      p = self.pos_
      while p < self.text_length_ and self.text_[p] not in stop_at:
          p += 1
      self.pos_ = p
  
imports: from fontTools.feaLib.error import FeatureLibError, IncludedFeaNotFound
  from fontTools.feaLib.location import FeatureLibLocation
  import re
  import os
label_desc: Use image node_id 8 for calling the Lexer obj's underlying member method code with example usage: obj.scan_until_(stop_at) without return types