@Override
      public CellBuilder setFamily(byte[] family) {
        builder.setFamily(family);
        return this;
      }
get a CellBuilder instance that already has relevant Type and Row set.
@param cellBuilderType e.g CellBuilderType.SHALLOW_COPY
@param cellType        e.g Cell.Type.Put
@return CellBuilder which already has relevant Type and Row set.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/Mutation.java