@NotNull
  private static String convertLeafExpression(@Nullable PyExpression condition) {
    if (condition == null) {
      return "";
    }
    else if (isNegation(condition)) {
      final PyExpression negated = getNegated(condition);
      if (negated == null) {
        return "";
      }
      return negated.getText();
    }
    else {
      if (condition instanceof PyBinaryExpression) {
        return "not(" + condition.getText() + ")";
      }
      return "not " + condition.getText();
    }
  }
@NotNull
  private static String convertLeafExpression(@Nullable PyExpression condition)