@Override
    public void visitIfStatement(@NotNull GrIfStatement grIfStatement) {
      super.visitIfStatement(grIfStatement);
      final GrExpression condition = grIfStatement.getCondition();
      if (condition == null) {
        return;
      }
      if (!BoolUtils.isNegation(condition)) {
        return;
      }
      if (grIfStatement.getElseBranch() == null || grIfStatement.getThenBranch() == null) {
        return;
      }
      registerError(condition);
    }
@Override
    public void visitIfStatement(@NotNull GrIfStatement grIfStatement)