/*
 * Licensed 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 io.prestosql.parquet;

import com.google.common.collect.ImmutableList;
import io.prestosql.spi.type.Type;

import java.util.List;
import java.util.Optional;

import static java.util.Objects.requireNonNull;

public class GroupField
        extends Field
{
    private final ImmutableList<Optional<Field>> children;

    public GroupField(Type type, int repetitionLevel, int definitionLevel, boolean required, ImmutableList<Optional<Field>> children)
    {
        super(type, repetitionLevel, definitionLevel, required);
        this.children = requireNonNull(children, "children is required");
    }

    public List<Optional<Field>> getChildren()
    {
        return children;
    }
}

@@ -836,25 +836,16 @@
 e final 
-Immutable
 List%3COpt
@@ -962,25 +962,16 @@
 quired, 
-Immutable
 List%3COpt
@@ -1089,16 +1089,37 @@
 ldren = 
+ImmutableList.copyOf(
 requireN
@@ -1152,17 +1152,14 @@
  is 
-required%22
+null%22)
 );%0A 

Declare field as a List