docs: def _get_base_command(self):
          """Returns the base command plus command-line options.
  
          Does not include input file, output file, and training set.
          """
          cd_command = ''.join(['cd ', str(self.WorkingDir), ';'])
          jvm_command = "java"
          jvm_arguments = self._commandline_join(
              [self.Parameters[k] for k in self._jvm_parameters])
          jar_arguments = '-jar "%s"' % self._get_jar_fp()
          rdp_arguments = self._commandline_join(
              [self.Parameters[k] for k in self._options])
  
          command_parts = [
              cd_command, jvm_command, jvm_arguments, jar_arguments,
              rdp_arguments, '-q']
          return self._commandline_join(command_parts).strip()