public static void addColumns(Scan scan, byte[][] columns) {
    for (byte[] column : columns) {
      addColumn(scan, column);
    }
  }
Adds an array of columns specified using old format, family:qualifier.
<p>
Overrides previous calls to {@link Scan#addColumn(byte[], byte[])}for any families in the
input.
@param scan    The Scan to update.
@param columns array of columns, formatted as <code>family:qualifier</code>
@see Scan#addColumn(byte[], byte[])
hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/mapreduce/TableInputFormat.java