/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.calcite.adapter.jdbc;

import org.apache.calcite.plan.RelOptCluster;
import org.apache.calcite.plan.RelOptTable;
import org.apache.calcite.plan.RelTraitSet;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.core.TableScan;

import com.google.common.collect.ImmutableList;

import java.util.List;

/**
 * Relational expression representing a scan of a table in a JDBC data source.
 */
public class JdbcTableScan extends TableScan implements JdbcRel {
  protected final JdbcTable jdbcTable;

  protected JdbcTableScan(
      RelOptCluster cluster,
      RelOptTable table,
      JdbcTable jdbcTable,
      JdbcConvention jdbcConvention) {
    super(cluster, cluster.traitSetOf(jdbcConvention), table);
    this.jdbcTable = jdbcTable;
    assert jdbcTable != null;
  }

  @Override public RelNode copy(RelTraitSet traitSet, List<RelNode> inputs) {
    assert inputs.isEmpty();
    return new JdbcTableScan(
        getCluster(), table, jdbcTable, (JdbcConvention) getConvention());
  }

  public JdbcImplementor.Result implement(JdbcImplementor implementor) {
    return implementor.result(jdbcTable.tableName(),
        ImmutableList.of(JdbcImplementor.Clause.FROM), this, null);
  }
}

// End JdbcTableScan.java

@@ -1124,16 +1124,42 @@
 il.List;
+%0Aimport java.util.Objects;
 %0A%0A/**%0A *
@@ -1308,24 +1308,21 @@
 el %7B%0A  p
-rotected
+ublic
  final J
@@ -1577,30 +1577,31 @@
 e = 
-jdbcTable;%0A    assert 
+Objects.requireNonNull(
 jdbc
@@ -1609,16 +1609,9 @@
 able
- != null
+)
 ;%0A  

Make field JdbcTableScan.jdbcTable public