public static TableIdentifier toIcebergTableIdentifier(SnowflakeIdentifier identifier) {
    Preconditions.checkArgument(
        identifier.type() == SnowflakeIdentifier.Type.TABLE,
        "SnowflakeIdentifier must be type TABLE, got '%s'",
        identifier);
    return TableIdentifier.of(
        identifier.databaseName(), identifier.schemaName(), identifier.tableName());
  }
@Test
  public void testToIcebergTableIdentifier() {
    assertThat(
            NamespaceHelpers.toIcebergTableIdentifier(
                SnowflakeIdentifier.ofTable("DB1", "SCHEMA1", "TABLE1")))
        .isEqualTo(TableIdentifier.of("DB1", "SCHEMA1", "TABLE1"));
  }