presto-parser/src/main/java/io/prestosql/sql/SqlFormatter.java/SqlFormatter/visitGrantRoles
class SqlFormatter:        @Override
        protected Void visitGrantRoles(GrantRoles node, Integer context)
        {
            builder.append("GRANT ");
            builder.append(node.getRoles().stream()
                    .map(Identifier::toString)
                    .collect(joining(", ")));
            builder.append(" TO ");
            builder.append(node.getGrantees().stream()
                    .map(Formatter::formatPrincipal)
                    .collect(joining(", ")));
            if (node.isWithAdminOption()) {
                builder.append(" WITH ADMIN OPTION");
            }
            if (node.getGrantor().isPresent()) {
                builder.append(" GRANTED BY ").append(formatGrantor(node.getGrantor().get()));
            }
            return null;
        }