def loadTab5File(sc, pathToSampleFile):
    """
    Loads a Tab5-formatted file into an RDD. The file is loaded using the Hadoop File API so we can create an RDD
    based on the tab5 format: [name]\t[seq1]\t[qual1]\t[seq2]\t[qual2]\n
    Args:
        sc: A Spark context
        pathToSampleFile: A valid Hadoop file path (S3, HDFS, etc.).

    Returns:
        An RDD with a record number as KEY, and reads as VALUE.
    """
    sampleRDD = sc.newAPIHadoopFile(pathToSampleFile,
                                    'org.apache.hadoop.mapreduce.lib.input.TextInputFormat',
                                    'org.apache.hadoop.io.LongWritable',
                                    'org.apache.hadoop.io.Text',
                                    conf={'textinputformat.record.delimiter': '\n'})

    return sampleRDD