<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def ReadFile(self, filename):
 """Reads artifact definitions from a file. Args: filename (str):
 name of the file to read from. Yields: ArtifactDefinition: an artifact definition. """

    with io.open(filename, 'r', encoding='utf-8') as file_object:
      for artifact_definition in self.ReadFileObject(file_object):
        yield artifact_definition