public final static int compareFamilies(Cell left, byte[] right, int roffset, int rlength) {
    if (left instanceof ByteBufferExtendedCell) {
      return ByteBufferUtils.compareTo(((ByteBufferExtendedCell) left).getFamilyByteBuffer(),
        ((ByteBufferExtendedCell) left).getFamilyPosition(), left.getFamilyLength(), right, roffset,
        rlength);
    }
    return Bytes.compareTo(left.getFamilyArray(), left.getFamilyOffset(), left.getFamilyLength(),
      right, roffset, rlength);
  }
Compares the cell's family with the given byte[]
@param left    the cell for which the family has to be compared
@param right   the byte[] having the family
@param roffset the offset of the family
@param rlength the length of the family
@return greater than 0 if left cell's family is bigger than byte[], lesser than 0 if left
        cell's family is lesser than byte[] and 0 otherwise
hbase-common/src/main/java/org/apache/hadoop/hbase/CellUtil.java