code: def request_load_source(self, py_db, seq, filename):
          '''
          :param str filename:
              Note: must be already translated for the server.
          '''
          try:
              assert filename.__class__ == str  # i.e.: bytes on py2 and str on py3
  
              with open(filename, 'r') as stream:
                  source = stream.read()
              cmd = py_db.cmd_factory.make_load_source_message(seq, source)
          except:
              cmd = py_db.cmd_factory.make_error_message(seq, get_exception_traceback_str())
  
          py_db.writer.add_command(cmdf request_load_source(self, py_db, seq, filename):
          '''
          :param str filename:
              Note: must be already translated for the server.
          '''
          try:
              assert filename.__class__ == str  # i.e.: bytes on py2 and str on py3
  
              with open(filename, 'r') as stream:
                  source = stream.read()
              cmd = py_db.cmd_factory.make_load_source_message(seq, source)
          except:
              cmd = py_db.cmd_factory.make_error_message(seq, get_exception_traceback_str())
  
          py_db.writer.add_command(cmd)
docs: :param str filename:
              Note: must be already translated for the server.