@classmethod
  @abstractmethod
  def parse(cls, filepath, filecontent, symbol_table_cls):
testing if Attribute.next_available extension is working properly
dataset/ETHPy150Open pantsbuild/pants/src/python/pants/engine/exp/parser.py/Parser.parse--crossover with--dataset/ETHPy150Open eoyilmaz/anima/tests/extension/maya.py/AttributeExtensionsTester.test_next_available_extension_is_working_properly