/*
 * 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.jmeter.report.core;

import java.io.Closeable;

import org.apache.jmeter.report.core.Sample;

/**
 * Describes sample writer basic operations.<br>
 * <br>
 * Basically a sample writer is able to write samples to an unknown destination
 * and close itself. <br>
 * 
 * @since 2.14
 */
abstract public class SampleWriter implements Closeable {

    /**
     * Write a sample to the underlying destination
     * 
     * @param s
     *            The sample to be written
     * @return The number of samples written at this time to the undernlying
     *         destination
     */
    abstract public long write(Sample s);
}

/*
 * 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.jmeter.report.core;

import java.io.Closeable;

import org.apache.jmeter.report.core.Sample;

/**
 * Describes sample writer basic operations.<br>
 * <br>
 * Basically a sample writer is able to write samples to an unknown destination
 * and close itself. <br>
 * 
 * @since 2.14
 */
abstract public class SampleWriter implements Closeable {

    /**
     * Write a sample to the underlying destination
     * 
     * @param sample
     *            The sample to be written (Must not be {@code null})
     * @return The number of samples written at this time to the underlying
     *         destination
     */
    abstract public long write(Sample sample);
}

Use a more descriptive variable name and point out, that the parameter must not be null.