code: private static boolean isNullRejecting(Collection<String> tableAliases,
              List<AbstractExpression> exprs) {
          for (AbstractExpression expr : exprs) {
              for (String tableAlias : tableAliases) {
                  if (ExpressionUtil.isNullRejectingExpression(expr, tableAlias)) {
                      // We are done at this level
                      return true;
                  }
              }
          }
          return false;
      }
docs: Verify if an expression from the input list is NULL-rejecting
  for any of the tables from the list
  @param tableAliases list of tables
  @param exprs list of expressions
  @return TRUE if there is a NULL-rejecting expression