presto-parser/src/main/java/io/prestosql/sql/parser/AstBuilder.java/AstBuilder/visitGrant
class AstBuilder:    @Override
    public Node visitGrant(SqlBaseParser.GrantContext context)
    {
        Optional<List<String>> privileges;
        if (context.ALL() != null) {
            privileges = Optional.empty();
        }
        else {
            privileges = Optional.of(context.privilege().stream()
                    .map(SqlBaseParser.PrivilegeContext::getText)
                    .collect(toList()));
        }
        return new Grant(
                getLocation(context),
                privileges,
                context.TABLE() != null,
                getQualifiedName(context.qualifiedName()),
                getPrincipalSpecification(context.grantee),
                context.OPTION() != null);
    }