private static void addColumn(Scan scan, byte[] familyAndQualifier) {
    byte[][] fq = CellUtil.parseColumn(familyAndQualifier);
    if (fq.length == 1) {
      scan.addFamily(fq[0]);
    } else if (fq.length == 2) {
      scan.addColumn(fq[0], fq[1]);
    } else {
      throw new IllegalArgumentException("Invalid familyAndQualifier provided.");
    }
  }
Parses a combined family and qualifier and adds either both or just the family in case there is
no qualifier. This assumes the older colon divided notation, e.g. "family:qualifier".
@param scan               The Scan to update.
@param familyAndQualifier family and qualifier
@throws IllegalArgumentException When familyAndQualifier is invalid.
hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/mapreduce/TableInputFormat.java